Center punch it...drill with a smaller diameter until you reach the tread diameter minus 1 or 2 mm, Then punch the hole with a grinded Rebar on wich you grinded some angles.. Like triangle on a conus. Once that is stuck, you can get the remains out.
THis is how I did it once..or replace the drum :omg: .
ZELENSIS, coachbuilt body from the 50's on a vw platform made in Belgium. Peter the heb detective