yes build a playdoh or plumbers putty dam around the hole to hold sand/water. you need a 1/4" glass bit to make a pilot but you can get a set of small sizes for a few bux on fleabay. I used a cheap 1/2" electric drill but I think a drill press would work best. you don't want much pressure just enough to feel the sand rolling between the saw and glass. drill 1/3 of the way through from one side then flip it over so you don't get breakout on the bottom side. I used pool filter sand mostly quarts but if you could get a fist full of sandblasting grit it would probably work better. took me over an hour to grind my way through but whateves its a hobby.
I think unless you already have an old holesaw/sand/drill. buying the $50 one on amazon would be the best bet as you can resell/rent it out after. The hole size you want is 3 7/8" anyway my 4" was a bit big.
You can also go to crystal glass and have there "experts" break your glass and send you home with a $90 bill.
