So I have a bunch of what looks like rock chips (were there when i bought the truck) on the rear side of the door windows. Where it sinks in toward the window. They have started to rust a little where it is chipped also. I'm wondering what i can do to fix this? Can i just put some rust remover on it and use touch up paint? Or should i sand it down? Or am i better off just taking it to a paint shop?