Farewell Cottered Cranks

someone on here came up with a genius solution using a plumbing thing that is like a claw of death and it pops em out.
but anglegrinding is all good- two ways of going about it-

1. the way you mentioned- through BB axle
   
2. cutting a notch carefully in the crank, on the underside, if you get what i mean i.e. the rounded bit not the arm itself, to relieve the tension and then prising off.
   H