You do have both the PAC and PCS, yes?

Yep

No... 04 is the black skin. 05 is the white skin, 06 is the brown skin.

Then do you have any idea why I can't get a skin to go over 06?  I used a skin that I know works because I've had it over other colors. 

Name it FitKoopa05, and make sure you have both a PAC and a PCS file.

Don't ever go above 06, that's just silly. Unless it's Wario, he goes up to 11.

05 is the black skin silver shell Bowser.  I already have a working Nidoking skin over it. 

I can't figure out how to change the Gold Bowser to some other skin.  I have skins for 01, 03, 04, and 05 that all work.  I applied the 01 skin (Groudon for me) to 00, 02, 06, 07, 08, and 09 as a test.  I just used copy/paste and changed the numbers.  After running that test the original skin changed to Groudon, but there were no other changes.  The Gold Bowser stayed as Gold Bowser instead of changing into a Groudon. 

So can anyone help?  I just want to know what number to use rather than testing numbers 10-99.  I use GeckoOS. 

If you're talking about things like Fire Flowers shooting Ice or stuff like that, you'd need to hex the items and put them in their respective folders like any other .Pac hack.

If you're talking about stuff like stacking, that's part of the GCT, which would be found in the "codes" folder on your SD Card. I'm pretty sure there are some GCT editing programs you can find on this site, but I don't use any of them and therefore I can't point you in any direction. Just know that they're here.

If you want to make your own GCTs, you'll need CodeManager (an exe for your computer) and this site here: http://www.geckocodes.org/

There's a Brawl section there as well, but you'll need to chose the codes by which version you have. (NTSC, PAL/KOR, NTSC-J)(North America, Europe, Korea, Japan)

I actually figured it out I think.  I downloaded BrawlBox to edit the CSPs.  Out of sheer curiousity, I started exploring the other two common files (common3 and common4).  All of the item mods go in common3. 

I'm using GeckoOS.  The majority of the mods were applied by my friend, so all of the standard files should be fine.  There are a ton of stage and character mods that work perfectly.  He never applied any item mods except that mushrooms can stack now. 

Basically, how do I apply item modifications?  I did read through this and didn't find an answer-

http://forums.kc-mm.com/index.php?topic=12169.0