Remove the battery.

To install a new battery:

Peel any residual adhesive strips from the frame.

Clean the frame with isopropyl alcohol and a lint-free or microfiber cloth.

If your battery comes with adhesive pre-installed, remove the liners and firmly press each cell into place.

If your battery doesn't come with adhesive pre-installed, apply a couple strips of thin, double-sided tape to each cell and firmly press it into place.