Deleting messages in iCloud.

I’m trying to delete selected messages from iCloud. I’m Struggling. Apple genius bar and advisors not much help. I have 4 devices iPhone 16e, new iPad Air, older iPad and iPhone 6s. My iCloud storage is maxed. How can I view my messages in iCloud and delete the ones I don’t want? Advice has me going in circles, disabling iCloud, then enabling to view the messages, back and forth.

1st thing is to delete a bunch of messages. Turn off iCloud on all devices? I can view the messages on the devices, but that’s not iCloud. I need to figure out how to access my messages in ICloud so I can see them and delete individually.