Its not the cap that you replace its the locking pin that slips into the cap. When you break the liitle tab at the top of the cap the remaining piece of the locking pin is still in the cap. Take a very small screwdriver(one used for eyeglass repair) and push the pin down thru the bottom of the cap. You should now be able to remove the cap. You should be able to buy the locking pin at a dealership, buy the locking pin before you break the existing one.