Converting Old (Unsupported) Mods To BG2EE

Hey all, I'm currently enjoying BG2EE (as are most of you, I'd guess).

I've seen the new mod list for BG2EE, and while many of the best mods are there, it's still missing a bunch of small, relatively unknown ones, many of which aren't even being supported by their authors anymore. There are lots of cool mods out there that will probably never get updated to BG2EE (for whatever reason), so I've been wondering if there's any way for players to do this themselves (for personal use only, of course)?

Here's an example of one such mod:

http://www.shsforums.net/topic/24786-rupert-the-dye-merchant-version-211/

Its last update was ages ago, but it's just such a fun, cool little mod that it would be a pity to skip it. I always install it when running BG2 - coupled with the avatar changing scripts, it allows for amazing customization of the party's appearance. And this is just one example; there are literally a dozen similarly 'minor' but very fun mods I'd like to include in my BG2EE runs.

So, is there any straightforward and (relatively simple) way to manually update these older mods to BG2EE status?