how do i get 5 lug tenzo rims to fit on it?!!

you can buy adapters.

Yes, that's the only way this will happen.

Depends on what lug pattern is on your Cav.. if its 5x100 then you probably out of luck. If its a 5x114 then you can do a conversion and it might work, but you also have to look at offset. If the Cav's offset is way off from the xB, then your wheels might sit way too far in or way too far out.