I recently got a few G1 figures and some of them had some chrome wear(Prime's smokestacks,some guns).I was just wondering if there is any way to fix this? I've seen some different kinds of paints,but I don't want to do any more harm than good to them.

 

only way to fix the chrome is to paint over the old stuff.

 

There's a company called ChromeTechUSA that specializes in chrome plating scale model car parts. I would take apart the toy and ship them the parts you want chromed/re-chromed.
Check out their web site. Chrome tech usa, Chrome plating service, vacuum metallizing, for plastic on model cars, toys and automotive interior dash pannels.
This is probably your best bet of restoring your parts.
They can also do gold-plating if you wish, but it'll cost you a few bucks more than chrome.