Subaru BRZ 2018 Owner's Manual page 396

4-3. Do-it-yourself maintenance
STEP 3
STEP 4
STEP 5
394
Remove the depleted battery.
To prevent damage to the key,
wrap the tip of the screwdriver
with protective tape.
Install a new battery with the
"+" terminal facing up, as
shown in the illustration.
Align the protruding part with
the slot and install the cover.