I've been told I need to deauthorize this app before
installing it on the replacement machine. However, I can't find a
'deauthorize' function in the app itself, nor in the Contribute
knowledgebase. Perhaps I was misinformed?
I think you were misinformed. I work on a PC. This
functionality is present in Flash, Dreamweaver, etc., but I never
had to deauthorize using Contribute (up to version 4, CS3 I don't
know yet). You can uninstall and install the program without
deauthorization, without problems.