How do I attach a wheel mesh to a wheel hub?

So I’m making a vehicle with more than 4 wheels, and I’m using the vehicles package ‘sky car’ as the base and changing the different meshes and colliders and stuff to the ones for a different vehicle. But to add more wheels, I need to make more wheel hubs and attach the new wheel meshes to them, otherwise they don’t rotate. How?

Since nobody ever answered my question, I just kept going without knowing until I eventually figured it out. The car has a script component called car controller. Under the first three drop-down lists, it will list which wheel hubs, meshes and effects are being used as parts of the car. At the top of each one is a field for typing in the amount of wheels the vehicle has. Just type in how many it needs, and extra slots for the different wheel parts will appear. Maybe someone, some day, will appreciate my answer.

EDIT: scratch that, it didn’t work. What else do I possibly need to do?!