Call Jeff at Rage Karts. He will likely have a scraper that attaches onto the end of a heat gun(or he will know who does). You have to let it get hot and press down kinda hard but it works great. The sooner you do it the better, like as soon as you come off the track. Will not jeopardize the tire, only make it better. Some people do this on a prep stand, but i prefer to do it with the kart on the stand and with the wheels bolted onto the axle. Do the rear tires first, take them off, then bolt the front tires onto the rear axle and do them. works like a champ.