Not quite the same thing, but all the Spitfires I flew (Mks I,II,IX,XIV, XVI and XXII) had a "jemmy" (crowbar about 18 in long) clipped to the inside of the cockpit side flap.
Never had to use one, but I would think the best way would be to use the chisel end to force the canopy side frame off the rails rather than punch a way through the perspex.
Never had any instruction on them at all !
Danny.
Last edited by Danny42C; 23rd Feb 2016 at 00:02.
Reason: "Smilie" wouldn't work !