Time Machine on slow drive to be ported to new drive

I have an old multi-partitioned external HDD with one partition being used for Time-machine.

I want this partition with Time-machine moved to a new SSD.

How do I go about copying a "partition"? unix dd? or rsync (don't believe this would work as hard links and sym links used by Time-machine?

Finder knows how to do this, almost nothing else does.

Hard links &/or permissions are the downfall usually.
Don't attempt to manually trim it as part of the copy process, just copy the whole lot. If you need to trim by size or date, do it separately.

Apple guide on copying - Transfer Time Machine backups from one backup disk to another

In brief:
Format HFS+
Set correct permissions system rw wheel rw everyone r
Turn off Time Machine
Drag the entire Backups.backupdb folder to the new drive.

Ask Different guide on trimming for size - Remove unnecessary backups from TimeMachine to get space