Been there, done that. I also freaked.

Remove the shock, and you'll probably find that the broken stub will come out rather easily. Try gripping with a vice grips if any is sticking out. If no-go there are many tricks to try. Heating it up a little with a propane torch will help, but be very conservative as you don't want to heat up the lower ball joint too much. I center-punched the stub, then started to drill out with a reverse-threaded drill bit (which turns in loosening direction) and the stub came right out. If you drill a nice hole but the stub remains, try the easy-out. Another approach: use a dremel tool with cutting disc to cut a grove in top, then impact screwdrive with regular bit to drive it out.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC