Slide the opening pick along the edge of the battery to loosen the adhesive.

The adhesive which holds the battery in place is soft. However, if you're struggling to pry out the battery you can place a heated iOpener on the rear side of the watch to loosen the adhesive. Apply the iOpener for at least two minutes.

Use constant, steady pressure to slowly pry the battery up, separating it from the adhesive securing it to the system board.

Mind the display cables and especially the Force Touch cable which covers the battery in one corner so you don't damage them when levering the battery out.

Make sure you don't puncture or deform the battery, as it can catch fire and/or explode if damaged.

Don't try to remove the battery all the way yet. It is still connected to the watch assembly.