Bet ya deleted some of the Google Play apps huh? Yeah. I did the same. Don't worry. It is a pretty easy fix. First you need to get the right downloads.
You can get the .tot file from: https://docs.google.com/uc?id=0B8FhtOwXHGPjVE4wbXFUVHR6SGc&export=download
(you will need 7zip to unpack this)
The flashing tool can be gotten from: https://app.box.com/s/ua760vn52db4ainj92hb
The .DLL for the mach itself can be found at: LGLS860_20120928_LGFLASHv14…rar (189,44 KB) - uploaded.net
And of course the LG unified driver blob from the LG support website.
OK, now onto the fun stuff. First, charge your phone!
It will still charge while soft bricked. At least 60%, preferably more. You do not wanna run out of charge while flashing.
Install the driver blob from the lg website.
Install the flash tool from the above download. do not run the tool yet. There is a small bit of patching to do to make it work. Inside the compressed file is a .dll file named "megalock.dll". This file needs to be copied to the folder that the install tool resides. Should be "C:\LG\LGFlashTool\LGFlashTool.exe" or such. Overwrite the existing file.
Grab your phone and get that thing in download mode. press Power, Volume up, and volume down at the same time. connect the phone to your computer with a trustworthy cable.
start the flash tool. The model config screen will start with it. check "Select manual mode." That .DLL that you downloaded earlier goes here. under S/W is the .Tot file. The action mode will be UPGRADE DL. Connection mode is USB. click "ok".
now click the coms port config (looks like a crappy cartoon version of the old fashion serial cable next to the gears button). Unselect all but port 1.
now comes the only really tricky part. for those of you still running Windows XP, see: LG Flash Tool - Free - no need B2B User/Pass - GSM-Forum
and for those who are running win7/8 open your device manager, and find the port called android usb diagnostic serial port (or something like that.) right click it, properties, port settings, and the advanced button. change the drop down menu for COM port number to COM41. click ok, then ok, and then finally, rescan for plug and play devices.
go back to the flash tool. hit start. your phone should be detected and it should start flashing. the program will
fail at 98%. this is ok. your phone is reflashed and working again!
now call sprint/boost and from another phone, and have em reactivate your mach. (dont ask, soft bricking these things breaks something on their end as well. they dont ask questions)