For holes and cuts, a soldering iron with a bladed tip at 150C can work well. For abrasions and scars, a heat gun, an infrared thermometer and some fine sand paper can restore things. Basically heat to roughly 110C and pat the (just) liquified surface with the sand paper, or it will appear glossy. I would suggest practicing on a spare piece of TPE (I know WM supply some spare TPE with their dolls). Some people just use glue. Good luck!