Like many folks that have an Nexus 7 Tablet got burned by Google continually updating the OS up to Android 5. The Nexus 7 tablet cannot handle Android 5 and it hangs and hangs.
I own other Android Tablets such as Samsung and they have some common sense and do not update beyond what it can handle.
The ZIP File at this link contains all the instructions (listed below) and everything you need to downgrade the tablet and root it.
** Go to Settings > About in your tablet and click the "Build Number" multiple times. It will tell you "You Are a Developer"
** Now go to Settings > Developer and enable debugging.
B) To Start This Process you need a DOS Command Window and run that in Admin Mode.
You may see: But it does not seem to matter.
G) Turn off Nexus 7 System Updates!!! --- STOP THE UPGRADE MADNESS!
- Scroll down until you see "Google Services Framework"