Garmin Flush Mount Kit for GPSMAP 500 Series 5" Displays Reviews:
INSTALLATION WAS A SNAP
For the template I would suggest being able to pull of just a small portion of the backing to enable proper positioning. Put some serations in the backing say 1" down from top...also make the adhesive behind this portion of the backing about half as sticky so you could remove if you dont get position right the first time. Would make install much less tricky.