Originally Posted by
gmt13
Although it's tempting to start with power tools, I'd advise using a hacksaw to define the upper and lower surfaces of the DO. Hacksaws will cut a relatively straight line, which can be then refined by light touches with a file (or even a dremel tool). I have found that you can screw something up with hand tools as well as power tools, but the damage is quicker and more severe with power tools.
Good Luck
-G
+1. If you do saw or grind out that tab, be very careful to follow the top line of the dropout. If you make it higher or lower than the other one, or the wheel will be canted in the frame.