Aluminium or steel frame? Heat is not an option for Al.
I sawed mine off and then used a file to remove the remining material. Sawing takes 5-10 mins with a good handsaw, filing takes 30 or so with a decent file. Of course, half the time is spent looking at the frame sideways to see where the actual tube starts. Being inexperienced with powertools, I wouldn't have liked to risk my frame trying to use one.

Ok, those times are for one single cable stop, but you can do the two triples in an afternoon for sure.