You would need an exporter of granny to max. Which sadly its something I can't give you too much tips about since I have only tried to import external 3d in Granny 2.1.0.5, not vice versa.
Although, if you google, there're plenty of exporters of granny to max like this one. However, I've never tried it and I think it doesn't supports animation.
If you have luck to extract it, then I can give you support to import it in Ragnarok, which is what I can deal with. So basically you have to: take the model+animation+textures, apply the new texture in 3d, and then export a new gr2 file with the right version. As a note, the textures on these models are particulary hardcoded in the file, you don't have too much options besides the one I'm saying, unless someone knows/share a way of how to decompile the texture in that file.
Edit: I remember now that there is a rsm emperium model inside the RO data. You can easily take it with animation if you follow my tutorials and then export it with a new texture as a new gr2 model.