Bob,
The upgrade process seems a little daunting before you embark on it; but stick with it - have you followed the instructions here? What happened? Can you Reveal AddOns in Finder?
It’s possible that you didn’t have RW6-compatible versions:
FormLoom 3 for RW6 is here.
Today Stacks 3 was launched.
FAQMaker is here.
Try updating them first in RW5. Good luck!