This is a challenging step. Do it carefully to prevent the spring bar from flying out of the wristband.

Use the tweezer to depress the spring bar so that it collapses by a few millimeters and pops out of the hole that was holding it in place.

Now carefully pull the other end of the spring bar to detach the wristband from the watch face.

Repeat steps 1 and 2 for the other wristband.