First off the only way right now (that I know of) to get on screen nav buttons is AOKP. I will leave that up to you on how to get that installed.
As for turning off the capacitive buttons this is how I did it.
1.On AOKP go to Settings>Navigation bar>Enable bar. If you don't do this first you wont have a way to navigate when the capcitive buttons are off.
2. Download a root file explorer. Root Browser Lite --> http://goo.gl/b9ISW This is what I will use.
3.Load up Root Browser and navigate to system>usr>keylayout. We will be looking for a file called "sec_touchkey.kl".
4. Select it and hit "Open as..." then "Text file" then "RB Text Editor"
5. Now we see this:
key 139 VIRTUAL key 158 VIRTUAL key 102 HOME key 217 SEARCHAll you have to do is option out the keys you don't want to work with a #. So if you are like me and think the home button is fine, it will look like this.
#key 139 VIRTUAL #key 158 VIRTUAL key 102 HOME key 217 SEARCH6. When you have the ones you want optioned out just tap the little disk icon in the top right. It will ask for root rights, grant it, saved.
7. Now just reboot and DONE!
Your keys should no longer work. They will still light up, but you cant use them.
Now onto the lights. Fellow Rootzwiki frequenter Jaxidian came up with this little work around and was kind enough to share it.
1. Go into Settings -> Display -> Custom Backlight Settings -> Edit other levels... -> And set every "button" field to 0 and save.
2. Turn your brightness settings to "Auto" either via your statusbar widgets/toggles or via the standard Settings -> Display settings.
3. Go back to Home, turn your screen off, wait a second and turn it back on. Notice that the button lights stay off! :-)
If you like to keep keep your screen brightness at Auto, then you're done! :-)
4. Now turn your brightness back to a manual setting. Notice that your buttons light back up. :-( That's okay.
5. Turn your screen off, wait a few seconds, then turn it back on.
6. Now they should be off and will remain off until either you reboot or you toggle the Auto field again (which toggling it simply brings you back to step 5 to fix again).
Hope this helps anyone that hates the capacitive buttons or just misses the on screen nav from the Gnex like I did. If I missed anything please let me know. Cheers!
Edited by Adam Metzner, 26 July 2012 - 12:37 PM.