To drill a lock cylinder, create a dimple on the lock's face, position a 7/32- or 3/16-inch drill bit into it, and drill via the lock's tumblers. Use a spraying lubricant when drilling, and drill with moderate pressure and speed. After drilling, push a screwdriver in the keyhole, and twist to unlock the lock.
When creating a dimple on the lock's face, use a center punch loaded with a spring or a jig meant for lock drilling. Create the dimple just above the keyhole and close to its edge. Use a power drill without a key for the chuck for drilling.
When drilling via the dimple, begin at a moderate speed. Spray a lubricant frequently at the point of contact between the lock cylinder and the drill bit. The lubricant serves as a cutting agent, prevents the cylinder from heating up and melting, and removes metal shavings that can clog the keyhole. By reducing heat accumulation, the lubricant also prevents the drill bit from becoming dull and losing its hardness.
Allow the drill bit to go through the tumbler's pins. Normally, the tumbler comprises of five or six pins. Apply moderate pressure on the drill bit when drilling to prevent it from breaking, getting jammed and overheating.
Once all the pins are drilled, use a screwdriver with a straight slot to unlock and re-lock the lock.