I actually had to use several programs and found out how to do it almost by accident when looking at papercraft models. I have no clue how to do it for HW2 models, but I must say, I never really liked the look of HW2 ship design. I think the designs and story went from something unique to "Look! We're driving huge ships based off real battleships...but IIIIIN SPAAAAAAACE!!!" And the story, my god, it was beyond horrible.
Anyway, you take the BigViewer and open the .big file for either homeworld or cata. Each model has 4 LODs that you can use for models but the counts on even the largest ships are only 500 polys so I don't see the need for anything other than LOD0.
You use 3D Exploration to convert the model and the textures to use in MAX, then tweak it accordingly for the DAE converter.
The problem arises when you try to convert it. Each ship has about 5-15 textures that are stored with the model, but the names are very similar, so you have to modify the textures list in the converter and rename specific textures. When I imported the frigate, half the textures were from the corvette.

On the plus side, it should be easy to make hi-res maps since the texture automatically seems to shrink or grow depending on the size. How to edit the mesh to higher polys though, i have no idea.