Go to an auto parts store or somthing of the sort or go google what a metal file is. Then once you get the file and the wheels try to put the wheel in and look where it rubs, once you know where the wheel rubs file down that part then try it again, if it still rubs file it down some more where its rubbing. Keep filing until the wheel fits in the fork and spins freely. The filing proccess should take about 30 minutes and check to see if the wheel fits every 5 min or so.