First your going to want to flash a recovery. I recommend TWRP, its the most user friendly recovery, there are other Recovery's such as cwm touch and all that but its a pain for me lol. LINK: http://androidforums.com/showthread.php?t=716281

After that, make a backup to your sdcard of your stock rom.

After that your going to want to flash a custom ROM, I recommend cm10, its the most stable updated version of android there is for this phone. LINK: http://androidforums.com/showthread.php?t=848107

Note that your also going to need to flash gapps for android 4.1, look that up on Google or I think if you check that post I made a comment with the gapps your need to flash. Hope this helps!

 

Rom Backups are your friend. 😊 we call them nands or nandroids.

I suggest an app like Titanium backup, as well. You can use it to backup apps and such, not the rom itself. You can also use it to freeze apps you are thinking of uninstalling before you actually do. It's good to search what apps can be uninstalled without issues but if you find out different you can unfreeze them and be good to go.

Make sure you only flash stuff that is exactly for your specific phone. Don't be afraid to ask questions.