Well you can use the papa importer/exporter to get it in a suitable format for the PA engine first. https://forums.uberent.com/threads/rel-blender-importer-exporter-for-papa-files-v0-5.47964/ Then you gotta replace the ant model with that exported thing. Might want to make it a mod tho, or back up the original tank model
You need to triangulate the mesh, add the bones and vertex groups, and apply location, rotation, + scale. If you don't know how to do bones, import an existing model from PA and check it out. Also check out it's vertex groups which control the mesh.
I have have explained in detail to one guy how to rig the model in 3ds max and texture in photoshop. I can add you to convo if you want.