Restoring Locked Phone (Phone Unavailable) - disk is full
I got locked out of my iphone - maxed out all attempts and is now showing "Phone Unavailable". I tried the recovery options in Apple Support website, have connected to Apple Devices app and completed the update download.
I am now trying to restore it but I am getting an error message "The iPhone could not be restored. The disk you are attempting to use is full. Removing files and emptying the Recycle Bin will free up additional space."
How can I do these - remove files and empty recycle bin - when I can't even get in the phone system, which is the primary reason for trying to recover and restore it. Please help on next step!
iPhone 12 Pro