Hi! I posted this question over on the PM forum but never got a response, so I figured I would try here.
I had tried to put this (http://forums.kc-mm.com/Gallery/BrawlView.php?Number=35769) Lucina texture meant for Marth over Roy. When I select Roy and choose a stage, it freezes on the loading screen. Other characters work fine. I checked the creator's website, and found the answer in the comment section. Apparently, I have to reduce the file size to 50% because Brawl can only load so much custom data.
Only issue is, I have no idea how to do this. If someone could give me directions on how, or point me to a tutorial, I'd be very appreciative.
Simple; before importing the textures, take each one and copy it, and make the copies one half the size, until you get to 32x32; Then, import a group size of them(e.g. Import 5 different textures that you just half-sized), save it as another file, and compare that with the original; keep doing this, until you get to the filesize that is about the same as the original Brawl file(not 50%, but under 100%); then you could try it.
Another option(If you have an Autodesk application, like 3DS Max or Maya) would be to export the model to the application, lower the polycount(Probably a button for it), and then reimport, doing a similar process as with the textures.