first off clean all pieces with rubbing alcohol or something similar. nothing with acetone!! and yes you must sand, but it is not abusive sanding and i did mine with 300 grit so its not as invasive as you are probably thinking. then lay down a light, light, light coat of something whether its primer, clearcoat, or your color. i used clear coat. then sand that even finer than your first sanding. very very lightly coat again and let dry. then, thin layer by thin layer, paint until you are satisfied then use a protection such as clear coat or something not so glossy. good luck and takes only a few hours.
2002 F-150 XLT FX4
5.4L Triton V8 Automatic
In memory of The BEAST Her Last Days