You'll need 3DSMax and a specific plugin for that.
> Which program should you choose? The two main modeling programs are Autodesk Maya and Max. They are both extremely similar and it doesn't matter which one you know. I personally prefer Maya. Once you are well acquainted in either of the programs, you can watch a tutorial for the other and catch up really fast. However the programs are a bit expensive. You can get student versions for free as long as you have a .edu email, however you cannot make money off of any assets that you make in the student version.
> While not a industry standard, you can download blender for free. It's a completely different interface than the other programs but you can create quality assets with it.
It wouldn't be that difficult to update the exterior model. Hell, I could do it in 3DS in a month or two given the appropriate amount of free time. This biggest challenge concerning the visuals would be the VC. It needs a complete overhaul in both modeling and the removal of PR (Photo Real) textures that should be replaced with new, custom drawn mapped versions.