How do I cancel my AppleCare plan?

Hi there,

See the following instructions: How to manage your AppleCare plan

If you have a monthly plan, you can cancel using the instructions under "Manage or cancel an AppleCare plan that's paid monthly".

If you have bought AppleCare+ and you have paid in full but you have not used it, you will be able to get a refund of the remaining AppleCare+ coverage. Contact Apple Support.

You don't. It's a one time purchase.