You'll need to make each group of tracks (left side tracks seperate mesh from right side mesh) seperate meshes and skin them to a skeleton. Then assign wheels to the resulting animated bundles. Look at existing code and tanks as a reference point. If you don't want to go as far as add extra detail like making the track mesh flex and such, then it should only take a real simple setup with an invisible dummy wheel on each side for the tracks. The wheel has to be in the same level as the visible/physics wheels using the EngineRollGrip grip type so that the track textures will animate.
Looks like the texture is oriented correctly so all you have to do is what I mentioned above.
Had it been a BF2 vehicle or a vehicle with the track texture oriented vertically, you would have had to flip the texture and uvmaps since BF1942 only supports scrolling the texture on the horizontal axis.
