How to move Time Machine backups to a new drive

Yes, I understand. We can no longer move TM backups from one drive to another. It had been possible in what should now be considered the distant past, and Apple even provided the instructions. Those instructions have since been removed, and it can no longer be accomplished.

Just start a new set of backups on another device. Put the other one aside until you are satisfied it is no longer required, then you can erase it.

IF you keep both drives connected to the Mac, Time Machine will alternate between the two drives when it does its automatic backups.

At any time, you may manually backup to either drive.

If you keep only one drive connected all the time, TM will back up to that and eventually will start to nag you that it's been X amount of time since your Mac was backed up to the other drive. At that point you can simply connect the other drive and let TM automatically update the backup, or you can run a manual backup to that drive yourself.

Can't be done.

If you were to explain the need to move them, perhaps another solution is possible.

Moving Time Machine backups is not recommended, because it can compound any defects that might exist AND introduce new defects that might invalidate the entire set.

You can ADD an additional Backup drive at any time, and a new stand-alone backup set will be created on the new drive. Then every-other backup goes to every-other drive.

In a few days or so, the "new" backup will not be so new any more, and the old backup can be removed.