Remove the battery.

Don't reuse the battery after it's been removed, as doing so is a potential safety hazard. Replace it with a new battery.

To install a replacement battery:

Dampen a lint-free cloth with some isopropyl alcohol (>90%) and use it to remove any remaining adhesive from the battery well. Don't use too much—avoid dripping any through the cutouts in the frame.

Peel and discard one side of protective liners on the new adhesives and apply them to the new battery, using your old battery as a reference for where they should adhere.

Peel and discard the remaining side of adhesive liners. Lay the battery in place and press firmly.

Remember: Don't reconnect the battery connector until you've finished reassembly!