Kevin, My opinion? Remove them yourself and take them there.
The trick is to take two credit cards, slip them under the round plastic covers over the screws, squeeze them together, and they pop out. With the sills off, use pliers, a punch, different screwdrivers, whatever to flatten the holes back out. The problem is that the metal is so thin that the holes drastically elongate and when you put the screws back in they easily, very, very easily strip. Taking the time to flatten the holes back out fixes this. Then use a qtip and dip a little POR15 on the holes to prevent rust. When re-installing, buy new screws if necessary because the old one will probably have corrosion, only use a screwdriver type socket and just snug the screws back in with locktite. I suggest using three fingers on the handle. Do not use a rachet or you will just strip out the screws. You will be amazed at how little effort it takes. You can even test one with the sills off because you can then see the holes from the side. You'll see what I mean with the sills off. With the holes fixed, locktite and screws in snug that is all that is needed. Go online too, they make high temp locktite.
BTW, when they strip the sills and find aluminum corrosion damage, ensure they cut out and reweld. Do not just patch. You should demand to see the sills with paint stripped before they move on.
