Mercedes-Benz GLA Operator's Manual page 81

Repeatedly tap the SmartKey against your
X
palm until battery = falls out.
Insert the new battery with the positive ter-
X
minal facing upwards. Use a lint-free cloth
to do so.
Make sure that the surface of the battery is
X
free of lint, grease and other contaminants.
Insert the front tabs of battery tray cover :
X
and then press to close it.
Insert mechanical key into the SmartKey
X
( page 77).
Y
Check the function of all SmartKey buttons
X
on the vehicle.
SmartKey
79
Z