Pretty easily done - there's a hole with solder in it towards the left of the board just above the ground trace that runs around the edges of the board. There is a 270 ohm resistor (bands are red/purple/brown/gold) that is vertical on the board, and attached to this hole.
No real need to drill anything. Desolder the hole (or just melt it, and get the positive lead to stay in that hole, and then the negative lead can be bent and soldered to the adjacent ground trace (you may have to remove green soldermask from gthe ground trace - easily done with a razor blade to expose copper).
That's it! Hope that was understandable - make it easy on yourself, no drilling required.
(PS - of course, remove the battery first if there is one)
Chris