A hacksaw will get them off, you want a vise to hold the part while sawing. Leave some excess material on the triple tree side. Then you file off the excess and try to match the curve of the main piece. Get a decent size (at least 10 inch) medium bastard half-round file plus a similar size smooth file, the bastard removes metal quickly but leaves scars while the smooth can leave a very nice finish in skilled hands. Next use wet/dry paper (you use it wet, under running water is best) to smooth it to whatever finish you want. Start with about 250 grit and then 400, 600 should be used for a really nice paintable finish. If you want bare mirror finish alloy then it takes a lot more effort!
You may find voids in the metal after cutting off bits. You can fill these with JB-Weld or equivalent for painting.