Here's another sneaky trick to get a clean cut in thin metal- - - -attach a piece of 1/2" plywood to the metal where you want the hole to be with 2 or 3 sheet metal screws in the area that's going to be cut out, and make the cut with a fine-toothed jigsaw from the wood side. The wood will reinforce the metal and give you a clean cut with no distortion of the sheet metal.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!