There are 2 easy ways to disconnect your device from iCloud — even if your device doesn't work and/or is no longer with you! You can still make the disconnection via icloud.com.
First, choose your situation from below:
I need to disconnect my iPhone or iPad. It’s still with me and still works.
I need to disconnect my MacBook. It’s still with me and still works.
I no longer have my device (iPhone/iPad/MacBook) with me, and/or it doesn't work.