Beat them out! But seriously,there's an internal thread in the center that you thread a tool into the cup.(Robb Nortier, British tool Co. sells the tool.)
Then tap them out from other end.
Beware, some repro bearing cups I've seen do not have the internal thread , making it really difficult to get the cups out- I actually used a small chisel and gradually tapped the cups out, done carefully it can be done but will at best damage the cups, at worst you could do damage to the steering head of the frame.
Vince
If you can't get any purchase on the cup to drift it out (non-threaded type) you can spot weld a piece of steel across the cup, you're going to fit new ones anyway- and then knock it out from underneath.
That thread is the same as the chaincase filler plug so if you have a damaged spare plug and it's of the brass variety it can be use to knock out the races.
I removed mine as Pete described. I just mig welded an old bolt minus head across the inside of cup. The heat makes them loose also. Of course you have scrapped them now. Ron
