Preface

In a mechanical keyboard, the part of each “key” that you see and touch is the keycap. Underneath the keycap is the switch, which converts your press into an electrical signal. On the top of the slider of the switch is a protrusion (typically cross-shaped) and a corresponding slightly undersized cavity in the keycap; when the keycap is pushed onto the switch it forms a strong friction fit. So, in order to remove the keycap, you just need to pull it straight upward.

Typically, it is not possible to do it with just your fingers because the fit is too tight and there is not enough room for a good grip on the keycap. You may find yourself trying to pry up from the side with a thin tool like a knife. However, this will twist the keycap and may break it or the switch. It will probably also scratch/dent everything around it.

Tutorial

With a keycap puller, it is a breeze. Position both wires underneath the keycap, twist until they are diagonal (as in the photo below), then pull directly upward.

Keycap puller in the correct position. All that is left is to pull directly upward.