I used a 4.5" Dewalt angle grinder, cost about $45. Some people use a dremel or saw-zall. The grinder was quick and strong, but doing the curved parts was kind of tricky. I went through about 3-4 thicker blades for cutting then used a smoother thinner blade to smooth the edges out.
With a dremel, I think it's slower but makes smoother cuts. I've never used a dremel, but I would imagine that using both an angle grinder and dremel together would probably give the best results. The dremel would be easier and more accurate around the curves.
After I cut, I painted the edges with black rustoleum paint to keep it from rusting. After that dried I put on the mastic tape because the edges were still sharp metal.
Also note that on the drivers side the washer fluid bottle is right behind the fender. I would drill a small or hole or clearly mark the bottom of the bottle on the fender, then be sure not to cut above it. I popped a hole in the bottle by accident. If you do pop it, you can get a plastic tank repair kit at any PePboys, so no big deal.
Hope that helps.
Chris
