Modifying the fenders is fairly straightforward. The lip will be cut off and the ends of the openings with be moved toward the fender's centerline. The opening's height will remain the same. | 
With the fender opening's centerline established, Tony lays out where the fender will be cut. | 
A cutoff wheel on a grinder is carefully used to remove the fender lip. |
Yes, it looks goofy now, but it's going to be better soon. notice the front cut's angle, which was done to cut in the flattest area of the fender and preserve its compound curve. | 
With the lip removed from the fender, the front portion was shortened a predetermined amount along the top of the opening. This will vary depending on the overall diameter of the tires used; it may be anything from two to six inches. | 
The shortened lip is clamped in place. note how the centerline on the rear portion of the lip was moved to the rear to keep the opening centered. |
Tony rough-cut a filler piece for the rear of the fender. This portion of the fender has a surprising amount of curvature. | 
The bottoms of the panels were shaped by wrapping them around the propersize pipe. When it comes to sheetmetal, it's often a matter of using what works. | 
With the lip clamped in place, tack welds are used to secure it to the fender. |