merging two vB forum user tables?

[kpmedia]

Back history that might be important: I have several forums, mostly vBulletin. All of them have been converted over from others (Snitz, Webwiz, phpBB, etc). I don't think I ever "properly" removed the extra database entries from the Impex process. I have to be honest, it looked a bit confusing. I actually had to rewrite most of the Webwiz one myself to make it work properly.

Anyway... I have two vB forums, and I want for the current users on Forum #1 (vB 3.8.1) to be added to Forum #2 (vB 3.7.4). I don't care about new users, they can sign up twice, this is for the existing 500+ members.

I don't want to import threads or anything else, I just want users to be added to the other forum. People are lazy, so they don't visit the new forum much. If I make it convenient in addition to the ongoing marketing, I'm betting at least 10-20% of them would take a few moments to visit and use it.

Is there any easy way to do this, be it via ImpEx, or through the mySQL databases directly? (I'm still a SQL query newbie, to some degree, so I'd need help if via mySQL access.)

To avoid identical users, I would go ahead and rename 2-3 folks currently in Forum #2, and then merge them later in the admin panel. That would be easier, I would imagine, than having to deal with dupe-user issues during said merger/import.

I hope that makes clear sense.

Thanks.

FYI: This is pre-sales, because if it works, I may buy a couple more licenses for a similar issue on another pair of forums, on another set of software where it's NOT possible.