Note: In this tutorial I will give links to sections where you can download the necessary files needed for 3g service; for LGNPST I will give you the thread where I got my version and it is up to you to find the link I describe because I do not want to be responsible for hosting the file. Also for those who are unaware, I DO NOT GUARANTEE that you will get 3g. This has been something new being reported on the forums and has not been officially announced by Metro PCS. Also, thank andyo70 for his thread.
Step 1: Downloading the necessary files and getting spc code. (Be sure you keep these folders in a space where you will remember them, or easily accessible such as Desktop)
Prl Link: 3020.prl
LGNPST Lab v1.2: http://androidforums.com/lg-optimus-m/254250-lgnpst-lab-1-2-better-than-my-fix.html
(In this thread, look through the replies until you see the post by asadullah saying "here's the mirror" along with more detail on the file. you will see that the "here's" is in blue, it is a link. Click it and download the file from Google docs. )
You will download a .zip file, but inside the file are three .rar files. Since it is in a .rar file, you will need a .rar extractor.
Step 1: Downloading the necessary files and getting spc code. (Be sure you keep these folders in a space where you will remember them, or easily accessible such as Desktop)
Prl Link: 3020.prl
LGNPST Lab v1.2: http://androidforums.com/lg-optimus-m/254250-lgnpst-lab-1-2-better-than-my-fix.html
(In this thread, look through the replies until you see the post by asadullah saying "here's the mirror" along with more detail on the file. you will see that the "here's" is in blue, it is a link. Click it and download the file from Google docs. )
You will download a .zip file, but inside the file are three .rar files. Since it is in a .rar file, you will need a .rar extractor.
Windows: Free RAR Extract Frog - Free software downloads and software reviews - CNET Download.com
SPC Code: To get this code which is needed, you can click this link CheckESNFree.com : The only instant, free, online ESN Checker click on the circle next to MetroPCS and type in your MEID in the bar provided. To find this, you can go to settings -> About Phone -> Phone Status and type in the digits under MEID DEC. Or you can take out the battery and in the slot you will see a white tab and you will see MEID above the bar code and a bunch of numbers to the right of it. type this in the bar and then click "Check ESN". The site will give you your SPC code which should be six digits. for example, my SPC is 076500, but yours will be different. Be sure to write down YOUR SPC code or memorize it because you will need it in the last step.
Step 2: Extract the files
Click the andyolgphonestuff.zip file that you got from the google download and extract the folder. As I said before, you will see the three rar files, but you will also see a 3014.prl file, a MS690ZV3_36.scr.txt file, and a readme.txt file. Ignore the rest and open the readme.txt file as it will guide you through the installation better than I can describe it. Do follow the readme closely and be sure to stop following the readme when it says "Make sure that where it says "Provision" it is set to "Upgrade". Do not ask about any of the other modes because I have no idea what they do or how they work." For the Shortcut option, I decided to skip that part and when I installed, I went to C://LG Electronics/LGNPST/ and selected the application that didnt have General in it's name, however you can access it however you want as long as it comes up and reads your phone.)
Step 3: PRL writing
Now that you have everything installed, make sure when you have the LGNPST lab open, you have your phone plugged in and make sure the aplication has identified your phone and it should show details in the box on the right. It'll have details of your phone including your phone number.
Now in the "Provision" box towards the bottom where you see "Upgrade", you will look there for a PRL/ERI tab. Click it, and it should take you to the tab and you will see checkboxes with labels like "Write", "Read", "PRL", and "ERI" as well as two little icons to the left of PRL that look like a folder and a trashcan. It should look like this.
Click the folder icon and find you 3020.prl file you downloaded, click the open and then check the box with "Write" next to it. Then hit the big button at the bottom that says "Start". A popup will show asking you to input your spc code. Input your SPC code then hit "Ok" and let the program do its things, AND DO NOT UNPLUG YOUR PHONE DURING THIS PROCESS. Leave your phone alone until the process is done. Dont touch it, dont look at it, dont even breathe on it. (lol jk, you can look at it or breathe on it, just dont touch it) During the process, you phone should reboot and come back to its lock screen, however DO NOT TOUCH THE PHONE until the application on the computer says it is complete. Once it is done, you should be updated to PRL 3020, and feel free to check your phone settings to be sure. If you are lucky, you may get the 3G icon on your statusbar, if not, you will still see a good old 1x icon (If you are unlucky, do not feel bad for I have it too)
Step 4: Enjoy (if you are lucky)
Again, I do not guarantee that you will get 3G. You might be unlucky like me and be stuck at 1x. However if you have 3G (you lucky basta**), then enjoy.
SPC Code: To get this code which is needed, you can click this link CheckESNFree.com : The only instant, free, online ESN Checker click on the circle next to MetroPCS and type in your MEID in the bar provided. To find this, you can go to settings -> About Phone -> Phone Status and type in the digits under MEID DEC. Or you can take out the battery and in the slot you will see a white tab and you will see MEID above the bar code and a bunch of numbers to the right of it. type this in the bar and then click "Check ESN". The site will give you your SPC code which should be six digits. for example, my SPC is 076500, but yours will be different. Be sure to write down YOUR SPC code or memorize it because you will need it in the last step.
Step 2: Extract the files
Click the andyolgphonestuff.zip file that you got from the google download and extract the folder. As I said before, you will see the three rar files, but you will also see a 3014.prl file, a MS690ZV3_36.scr.txt file, and a readme.txt file. Ignore the rest and open the readme.txt file as it will guide you through the installation better than I can describe it. Do follow the readme closely and be sure to stop following the readme when it says "Make sure that where it says "Provision" it is set to "Upgrade". Do not ask about any of the other modes because I have no idea what they do or how they work." For the Shortcut option, I decided to skip that part and when I installed, I went to C://LG Electronics/LGNPST/ and selected the application that didnt have General in it's name, however you can access it however you want as long as it comes up and reads your phone.)
Step 3: PRL writing
Now that you have everything installed, make sure when you have the LGNPST lab open, you have your phone plugged in and make sure the aplication has identified your phone and it should show details in the box on the right. It'll have details of your phone including your phone number.
Now in the "Provision" box towards the bottom where you see "Upgrade", you will look there for a PRL/ERI tab. Click it, and it should take you to the tab and you will see checkboxes with labels like "Write", "Read", "PRL", and "ERI" as well as two little icons to the left of PRL that look like a folder and a trashcan. It should look like this.
Click the folder icon and find you 3020.prl file you downloaded, click the open and then check the box with "Write" next to it. Then hit the big button at the bottom that says "Start". A popup will show asking you to input your spc code. Input your SPC code then hit "Ok" and let the program do its things, AND DO NOT UNPLUG YOUR PHONE DURING THIS PROCESS. Leave your phone alone until the process is done. Dont touch it, dont look at it, dont even breathe on it. (lol jk, you can look at it or breathe on it, just dont touch it) During the process, you phone should reboot and come back to its lock screen, however DO NOT TOUCH THE PHONE until the application on the computer says it is complete. Once it is done, you should be updated to PRL 3020, and feel free to check your phone settings to be sure. If you are lucky, you may get the 3G icon on your statusbar, if not, you will still see a good old 1x icon (If you are unlucky, do not feel bad for I have it too)
Step 4: Enjoy (if you are lucky)
Again, I do not guarantee that you will get 3G. You might be unlucky like me and be stuck at 1x. However if you have 3G (you lucky basta**), then enjoy.