That would be the situation where you have to do it manually then. You make a new folder, and then copy and paste the Steam games into it, plus like a half-dozen other steps, which would be the 2nd way here:
https://support.steampowered.com/kb_...7418-YUBN-8129
I printed out that post and also had all of my log-in info, just in case. Read their instructions several times, and get it straight in your head before you start on it. If you've got very many games, it could take several hours, but that is what I used on my laptop. I used the Steam app and Manage Library on my desdktop, which has 3 drives, which went much faster, but still took a while...