Maybe I’m crazy - but moving this content was easy for me. I just moved the content files to another drive and deleted them off C:
When Cubase starts up again it’ll say the files are missing, and give you an option to locate them. You’ll have to manually find each individual file (there are quite a few) - should take about 20 minutes. After that, Cubase has links to all the content files at the new location, and will start up normally.
No registry change, no installation hassles - just move the files, delete them from original location, boot up Cubase, locate files. Done.
Have done this for multiple installs over the last 3 or 4 years.