For the codpiece, I normally use a heatgun and the wrong-end of a small screwdriver. Be careful not to heat too much, or the entire piece may warp. Heat a small area, test it with the ball of the screwdriver, heat, test...until you get what you're looking for.
Don't be afraid to screw it up. It's a DENT, for crying out loud. Not supposed to be too perfect. 