[Zipperton]

Well, for now at least, Sigg hasn't put anything on RDXDiskUser. So you can just go to WTF\Account\<username>\SavedVariables and make a backup of RDXDiskUser.lua along with the addon by the same name. I haven't tried yet, but you can probably use the addon's lua and toc files as a template and make your own disk too. That would probably be the safest route, in the long run.

EDIT: Ok, figured it out.

1. Make a copy of the RDXDiskUser addon and name it ThemeDiskMNKyDeth or whatever you prefer.

2. In that folder, rename RDXDiskUser.toc to ThemeDiskMNKyDeth.toc. Then open up both the toc and lua files and replace all occurrences of RDXDiskUser with ThemeDiskMNKyDeth. Don't worry, they're really short files that are really easy to read.

3. Put the new addon in your wow addons folder and fire up the game. You now have your own RDX disk. Migrate your theme/bindings/whatever to the new disk for safe keeping. Backups can be made by backing up both the addon and the .lua file by the same name in your saved variables folder.