I think you have to hack off bottom of fender but leave some at top to hold licence-plate and turn-signals.
Dremel may be too small for this. Cutting disc melts plastic fender and it just sticks to disc. Smaller teethed cutter will work, but it's almost not big enough to penetrate.
I draw a line for cut, then use jig-saw. Or a sawz-all.Or angle-grinder. Or you can hand-cut it with hacksaw. Many options. You can even take the Alcatraz approach and nibble off little at time with end-nippers or dykes. Any mistakes will be minor and easily corrected.
