If you are serious about offering this service I would strongly urge you to invest in a course of training, it easier than you think to inflict serious bodywork damage to a client vehicle will will result in costly (at your expense) bodywork repairs and possible re-spraying paintwork
Paintless Dent Removal (PDR):
(PDR) is a highly skilled process in which minor dings and dents are removed from an automobile's exterior without creating the costly and time consuming need for traditional body shop repairs. The process involves the use of custom designed dent removal tools that are applied to the inside skin of a vehicle's sheet metal, to begin the repair process, a dent technician gains access to the inside skin of the metal via an automobile's windows, headlights or other access point.
A fluorescent light is then used to illuminate the damaged area. The technician then drags the tip of the dent removal tool with leverage, over the damaged area in a fluid, pumping motion. In less than an hour, will be able to repair dings and dents on any panel of any metal vehicle, including the car's roof, trunk, and hood as long as the paint has not been fractured or damaged prior to the repair -