Eye protection a must. (Safety meeting of the day). Dremel, with a 90 degree adapter and the large, 1.5" cut-off disk.
IMO, the 1.5" cut-off disk are a bit much for the standard dremel tool, which tends to cut-out on thermal overload. Your track cutting project may be slowed a bit by the equipment limits. I also use a bench disk sander to true track ends.