Drilled a bunch of 'em with ease. The only breakage was when I dropped a saw on it (don't ask...). The only thing that I try to make sure of with thin glass like that is not to crank the bulkhead fittings on too tight so there isn't a horrid amount of pressure on that little glass, and obviously absolutely no chance of any solid pipes connected to it getting knocked as a strong torque will blow the pane out with ease. 
sump's 1" rule is a good idea - I followed the engineer's rule I'd seen posted which was to keep 1.5 times the radius of the hole space between any edge and a hole. 
 
Dremel is way easy for these - should take you 10 mins MAX for a 2" diameter hole. 
		
	
		
		
		
		
		
	
		
		
	
	
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