Hi there and a big welcome to EAB!!!!
The best way forward is to format your Workbench partition only and reinstall the Workbench pack of your choice. There is no upgrade pathway, apart from just writing over the top of your previous install but that will break more than it upgrades and will leave redundant files.
You can easily point any ClassicWB pack to your other partitions by using the Assign system built into the ClassicWB. Please see the following tutorial:
http://classicwb.abime.net/classicweb/tutorials.htm
