I have replaced the ones on my 07 with painted covers. It wasn't a big deal. Fairly simple and straight forward. I found that on the right side, you remove the battery for full access to the cover and no problems. The left i tighter, but isn't that difficult. The gaskets sit into seams, so they won't leak. You won't have much problem doing it yourself. Just remember you need a deep socket for the long stemmed studs. Other than that, I can't think of anything that is in your way. You'll like the look when it's done.
Black '07 4.0 coupe. 19" GT Wheels, Bullitt susp & GT brake upgrade, GT500 strut plates, Dynomax exhaust w/GT mufflers, S/D Coil, Live Wires, JLT CAI w/Diablo tune, Hood struts, IPU, GT MyColor, Leather Pwr Seats, 13 Boss Strg Wheel, a/dim mirror, Homelink, amb light console, Ford Nav/SYNC, hood scoop, qtr & side scoops, r/w louvers, GT500 spoiler, CS/GT frt & rr bumpers, rad ext & batt-m/cyl covers, underhood caps, plenum cover, tloc 7.5 w/3.73's, Seq t/lights, trunk switch. Whew!