Actually, if you only want to re-texture something, you don't need oxygen at all. Re-texturing BIS addons used to be the only way to make "new" addons, I believe, which was before O2. If you search the ed depot, you can find a *few* tuts on re-texturing models, including a program to do it for you. I'm afraid I can't help you much on it though, because I've successfully retextured *some* models, while being unsuccessful at retexturing others (mainly because my textures come out wrong when I convert them).
To get you started, I'd look at these links:
http://www.ofpec.com/editors/resource_view.php?id=9http://www.ofpec.com/editors/resource_view.php?id=56http://www.ofpec.com/editors/resource_view.php?id=348However, when it comes right down to it, things are *usually* pretty simple (like I said though, sometimes I've been unsuccessful doing this). Basically, how I do it is as follows:
1) I use a word processor called "Text Pad" (free to download I'm sure), which allows me to open up a p3d file and view it as "text" (just a bunch of random symbols).
2) In the open file, everything will be nonsense.... EXCEPT for the paths to the textures. The textures are almost always located in the same pbo file as the p3d model, so you just do a search for the name of the pbo.
3) The path to the texture should be in the form "\pbo name\subfolder\texture.p3d"
There could be any number of subfolders in the pbo, or none at all. I'm assuming you have a basic knowledge of how to make pbo's for you to understand this, BTW.
4) I then do a find/replace operation to change the path of all the textures, so that it is now "\my pbo name\my texture.p3d".
It's as simple as that... sometimes. Anyway, either check out the above tutorials/tools, or try my method. Hopefully it will eventually make sense to you. Keep in mind, I can't always get this stuff to work though, so I may not be the best person to ask.