Ummmm... did you get the glass Tempered already?
If so, you CANNOT CUT tempered glass. It will SHATTER. Tempered glass must be cut prior to getting tempered (baked at a high temperature)
If you did not get tempered glass, then I honestly have to ask why not? Not having tempered glass on a cocktail is dangerous. A wrong move with your hand up above the joystick into the glass and it will break and slice right into your hand. (Opposed to the 4x+ stronger glass you get by tempering, which also when hit that hard would shatter into thousands of pieces that would not slice your hand.)