i have the spacers in the back not the front. to flip the fronts its accually pretty hard on newer ones and i wouldnt suggest doing it it would be better to get spacers in the back and front.
however, if you want to try it what you need to do is pop out the bead of the tire on both sides of both front tires and remove the valve stems and put in flush mount valve stems. then you have to drill new holes on the other side and put in new valve stems