Aronne + BS 5 Lever Deadlock
Drill to pick:
Measure 18mm up from the top of the keyway then 15mm towards bolt.
Use a 6mm hard-plate drill bit followed by a flat ended drill bit to completely open up the hole without damaging the levers.
Drill for the stump:
Measure 18mm up from the top of the keyway then 20mm towards bolt. This lock has a fairly wide stump so 2 or 3 consecutive holes may need to be drilled to remove the stump. Use a 6mm hard-plate drill bit.