Never pull in a direction other than straight up. Pulling at an angle poses a high risk to damaging the underlying switch.

Position the wired keycap puller so the wire ends are horizontally aligned with the key and the flat ends of the wires rest under the key.

Rotate the wire 45 degrees and pull straight up to remove the key. This may require a bit of force, especially if you have never removed the keys before.

Remove every key using this method.