Short Version: *Give Up*
Long Version:
Okay, there are a lot of problems with what you want to do.
1) So you have the iso, and that's great!
2) Dumping the files from the iso to your hard disk.
To my knowledge the ability to dump the internal files from a nintendo iso has *only just* been accomplished for the *gamecube* via a program called GCTool. So unless you're able to write your own extraction program, which would also involve cracking whatever file system nintendo has used, don't expect to find a program on the internet that can do it for you.
3) Okay, assuming that you now have the iso's files dumped to your hard disk, you actually have to locate the model files. This is harder than it sounds because naming conventions can be really crazy.
4) So you have the model file. Now what? I have no idea what format Nintendo uses for their models for Wii isos, but DO NOT expect them to be in 3ds format. Nintendo almost always exclusively uses their own model formats, and these will definitely not open in a conventional 3d modelling package like maya, blender or 3dsmax. Again, to my knowledge, a converter does not exist. The one for certain gamecube models doesn't even export bones or animations yet! So you'd then need to write your own model converter, which will probably require that you have knowledge of the format that they used in the first place.
5) Go to short answer
Basically, don't expect to find what you're looking for on the internet, so unless you are capable of writing your own programs to do the above things (you are MUCH smarter than me if you can), what you want to do is pretty much impossible.
Oh, and I'm not advocating this either, I'm just saying HOW it would be done. I'm not sure, but I think the latest laws on intellectual/virtual property copyrights say that this is illegal. (But I'm not a lawyer, I'm just a scientist, so what do I know lol?)
