Removing a broken disk from Windows 2008 R2 "Destination list"

I am running backup of a Windows 2008 R2 server by rotating 4 disks – always 2 are out of the office.

Now one of the discs has broken and been replaced. I now want to remove / delete the broken disc from the “Destination” disc list.

I have looked into the command “wbadmin enable backup [-removetarget:<BackupTargetDisk>]” but as I can see this command
needs the backup disk to be connected to the server? (in the help info it is listed: “Requires you to specify the location as a 
disk identifier” – which I think means it has to be connected to get the disk identifier?)

I am looking for a command that let me use ex. “serverName 2013_08_09_10:00 Disk_03” as parameter for removing the disk.

Hopefully this is possible?

Regards
Harald