Insert a 1/8-inch drill bit into your drill.
Pour cold water into a spray bottle.
Drill a 1/8-inch hole into the top corner of the windowpane. Spray the drill bit with the cold water, as you are drilling, to keep the bit cool. Keeping the bit cool will prevent the glass from cracking as you drill.
Drill an additional 1/8-inch hole in the lower corner of the windowpane by following the same directions.
Leave the holes open to allow ventilation or cover them with a piece of tape to close off the vents.