I believe theres a little opening to put a screw driver in and you can turn the little star wheel. Give it a couple of clicks and you should be able to feel it looseing up. On the back plate, they might have a little plug in there to keep the dirt out you will have to take them out if there still there, then just put em back in. I would jack it up to do it, makes it easier to feel the wheel free up, good luck.
