I've used two methods, with similar success, the latter being faster.
Hacksaw to cut part way through stay, then two pairs of hefty mole grips, one pair to grip the part that is staying, I wrap that part in something protective, the other side of the cut I use the 2nd pair of moleys to pivot the metal and enlargen the cut until it gives up and breaks - this usually takes only a few seconds.
The cut is sharp, but mine have always come with some kind of rubber boot thing to go on the end.
The second cleaner and quicker method is a dremel.