Go to Park Operations and tell them about the broken leg. They will give you a form thingy to fill out. After that you get a booklet that allows you to sign-up for a time (you can only do this for one ride at a time). If you want front seat, tell the ride-op that you want front seat specifically. On rides that you don't sign up for i.e. Antique Cars, just go up the exit. It works out nice. Have fun!