move your steamapps folder to your 2nd drive (somewhere other than Steam's future location) and reinstall steam on the 2nd drive, then move the steamapps folder in there.
It should work like that.
This is what I do.
Also, a fresh installation of Steam will detect if any of your games are now being delivered via the new CDS, and may require you to convert them -- a quick process -- before playing. When I reinstalled Steam earlier in the year, I'd estimate that about half of my games needed to be converted.
I have another copy if my friend does not accept the game once he gets back his internet lol.
Haha, alrighty.