I have all EPs and all stuff packs, and a ton of custom content. My Mansion & Garden stuff pack simply stopped loading a couple of days ago. There is a very suspect line down the middle of the back of the disc, and one half is now darker than the other. I'm guessing this means the disc is fried.

I believe I understand what I need to do, but I wanted to check with the game masters here before actually trying it.

I think I can back up my current Sims 2 files, and uninstall my current M&G. Then install a new M&G, and just slip all of my backup content files into the appropriate place.

Is this correct, or will it not work because of a different registration code? Can I use my previous registration code with the new download? Am I completely wrong in what I need to do? If so, what is the correct way? Or have I just lost everything?

This is good! I definitely have a preference about who I'd like to hire, and I'm glad it doesn't have to be random anymore.