How to un-encrypt my Time Machine back up disk
I have an external USB hard drive that I back up to using Time Machine. I've been using the disk for years. I've just noticed in the Time Machine preferences that it says the disk is 'encrypted'. I presume this means that I must have set up a password for the disk so that if someone plugs the disk into a different computer they can not access my files without the password?
Trouble is I can't remember what the password is.
How do I un-encrypt my disk / TM backups?
Do I have to use Disk Utilities to wipe the disk clean and then resume TM? That could take hours...
MacBook Pro 15″, macOS 11.2