Well, if you're not comfortable doing it, then I guess contact them about a replacement?
There is always a chance that the replacement could arrive broken or something, so if it's a small paint chip that you can fix yourself, I'd do that. If it's in an obvious spot, and you are worried about wrecking it, contact SS and see what they say. Maybe they'd agree to let you try to touch it up first, and if you're not satisfied with the results, they'd replace it? Worth a shot.
I'm not much of a painter either, but I successfully touched up some similar paint chips on my Iron Man Mark VI maquette and Venom Comm (even mixed some colors to match!). Just get a really tiny brush and some acrylic model paint...