My old Time Machine backup drive (external USB) is now almost full. I have purchased a larger drive and want to switch to it for Time Machine, migrating all my old backups to the new drive's archive.
I presume that I start by copying the Time Machine archive from the old backup drive to the new one. Then it seems I need to use tmutil associatedisk but the man terminology is rather confusing. Can someone give me the right parameters? Assume my system drive is called BootDrive, the old TM disk is OldTMDisk, and the new TM disk is NewTMDisk.
The iMac runs OS 10.13 (High Sierra).