Pontiac 2007 G6 Owner's Manual page 104

Battery Replacement
Under normal use, the battery in your RKE
transmitter should last about four years.
The battery is weak if the transmitter will not work
at the normal range in any location. If you have
to get close to your vehicle before the transmitter
works, it is probably time to change the battery.
The KEY FOB BATT LOW message in the
vehicle's DIC will display if the RKE transmitter
battery is low.
Notice: When replacing the battery, use care
not to touch any of the circuitry. Static from
your body transferred to these surfaces may
damage the transmitter.
104
To replace the battery in the RKE transmitter do
the following:
1. Insert a flat object, with a thin edge, into the
notch located below the vehicle locator/panic
alarm button, and separate the bottom
half from the top half of the transmitter.
2. Remove the battery and replace it with the new
one. Make sure the positive (+) side of the
battery faces up. Use one three-volt, CR2032,
or equivalent, type battery.