Welcome in the forum, Jeff.
No chance to use P15_6 and P15_7 (USB dedicated) pins for CAN. You will have your board modified to test it (cut wires, solder bridges... ah1 I really like that!!!) <-pure sarcasm!
You will need CAN bus drivers and receivers to confirm to the electrical specifications.
Roger that, that was the conclusion we came to as well. Luckily we had some headers drawn out that we were able to use to make sure everything else is functional.
Sorry for the late reply, thanks for the response.
You're always welcome!