Locate the battery and area where a strip of wire is connected to the motherboard.

Use a nylon spudger or something which you can easily push back and slide the wire out carefully from the motherboard connector.

Then peel back the tape connecting the wire to the battery on both ends and lift the wire off the battery.

Gently slide a plastic spudger between the battery and the housing to free the adhesive. Work the spudger from side to side to gradually free the battery.