OK, first and foremost, to flash ANYTHING, you have to install recovery. We were lucky enough to have a working 2nd Init recovery. You can get it by going here:
http://androidforums.com/motion-4g-all-things-root/665972-985hpakick-2nd-init-recovery.html
Once you install it, open it, tap the top button, then the bottom button, and that will boot you into the Recovery menu. From there, to "Flash" something, you have to have that "something" on your internal or external memory. The buttons for the recovery menu are as follows:
Code:
Recovery Buttons:
-Vol + move up one menu item
-Vol - move down one menu item
-Home - switch between internal and external memory
-Back - go back to the previous menu
-Power - Select current menu item
Once you have recovery navigation mastered, you can start to flash things. If you want a custom ROM, check out BobZ CyanogenMod 10 here:
http://androidforums.com/motion-4g-all-things-root/709736-rom-wip-cm10-0-0-l0-bobz.html or PlayfulGod's CyanogenMod 10 here:
http://androidforums.com/motion-4g-...m-cyanogenmod-10-lg-motion-4g-lgms770-l0.html both of them are pretty complete, but there are issues with them both.
There are steps listed in both of those threads as to what you need to do to "flash" them through the recovery menu. FOLLOW THE DIRECTIONS to the letter, or you may regret it.
If you just want a custom kernel, there are a few of those bouncing around too. I would recommend GameTheory's Freedom kernel, which bypasses all MorningCall security checks, allowing you to remove any app from the phone, and also allows you to overclock your Motion's processor. You can grab that here:
http://androidforums.com/motion-4g-...el-ms770-loki-freedom-kernel-overclocked.html
If you have any other questions, take a look at the ATR (all things root) guide here:
http://androidforums.com/motion-4g-all-things-root/609954-lg-motion-4g-all-things-root-guide.html
Hope that covers everything.