Apple - How can I disable the caps lock key?

Just use the Keyboard pane of System Preferences.

Click "Modifier Keys", and set "Caps Lock" to "No Action".

n.b. This setting can be different if you have more than one keyboard.

In System Preferences, go to Keyboard > Keyboard > Modifier Keys… From the popup that appears, you can change caps lock's function to another modifier key, or to "No action."

The options available in the pop up menu: