Here is how I enlarged Tracker wheel openings. I used tin snips, a couple of cresent wrenches, a body hammer and a bucking dolly.
I marked out how I wanted the wheel openings to be. On this set I went 3 1/2 inches from back of fender at bottom and started my openings from there. I used a piece of gas welding rod to flex into position so I could mark it on fender (an extra set of hands really helps if you do it this way).
I used the cresent wrench to straighten out the bend on the wheel opening. Then used hammer and bucking dolly to flatten out the area where my new opening blended into the factory opening. (take it easy here so you do not bend up fender with hammering.) then start bending the curve in stages just a small bend at a time. Using the cresent wrench I made the metal bend at the cresent wrench, not just bending with the cresent wrench.
At the bottom of fender, where it wraps around the body, I reduced the bend area to about 1/4 inch and made a couple of cuts up to the bend line to allow it to make the compound bends.
I did the same thing on front of fender.
The paint will chip as you sharpen the bend, and will need to be touched up. This is how it looks now.