it will crack... slow down.... don't put too much pressure on it. i'm sure i was a little bit annoying. =) it came out perfect and it was a good inch thick of glass on top.
once the top hole was drilled, he drilled one on the side, closer to the opening of the vase. this is where the cord would come.
i stuck the wire through the side hole, then slid on the white rubber end cap, then stuck the end through the hole on the bottom of the vase (top of the lamp).
once the wire is through the top hole, attach the rest of the lamp kit in the order 