Forum Thread: How Can I Disable the Front 3 Buttons

You definitely can. Here's how:

• You'll need a root file manager with a system writable text editor - I recommend ES File Explorer for this, but feel free to use whatever you want. If using ES, hit menu, Settings, go down to Root Settings, and check Root Exploerer, Up to Root, and Mount File System.
• Now scroll to the System > usr > keylayout. Once there, longpress the Generic.kl file, hit Open As, hit Text, and select ES Note Editor.
• Find the line that says "key 139 menu" and change it to "#key 139 menu". Do the same for the line "key 158 back", changing it to "#key 158 back".
• If you want to disable the Home button, change "key 102 movehome" to "#key 102 movehome".
• Save the file and go back to the "keylayout" folder.
• Now go to the file secUNDERSCOREtouchkey.kl
• Put a "#" in front of key 139 and key 158 (also key 102 to disable Home key).
• Save the file and reboot.

For readers that are running AOKP and don't have the on screen buttons, here's how to turn them on. If you're not running AOKP but want the buttons, there will be a post shortly detailing how you can do that.

• Go to Setting > Navigation Bar > Enable Bar

Hope this helps!