if bearing race is stuck hard it will be very difficult to remove without damaging your case. If you have access to a dremel, you may be able to carefully grind away two points of the race that will allow you carefully pick one section of it out and the remaing piece should then collapse enough to come out with ease.
A more feasable method will have you back in the oven. High temps on a totally stripped case will not effect it. the 300 range on an operating motor is because of the piston expanding against the cylinder wall increasing wear.
So, try this. find a metal tool, socket wrench handle, drift or punch or something that will fit against the bearing race without contacting the case itself. It needs to be metal and preferably a heavier tool for greater temp absorption. Once you find the tool that fits nicely, throw it in the freezer.
Preheat your oven for 20 minutes. set your case in and allow it to come up to temp. While it's heating, have gloves ready, a cutting board or something to tap your case on without banging up the counter or damaging your case.
When ready, pull the frozen tool out of the freezer, then the case out of the oven, touch the cold tool briefly to the bearing to cause it to cool and contract faster than the case...ONLY BRIEFLY, then tap case on cutting board and hopefully leave the bearing race on the board.
Holding tool to bearing too long will cool case as well. Likewise, waiting too long from taking the heat from the bearing will give time for it to transfer back from case and heat again before tapping the bearing out.
It sounds like a big pain, but it's easier than making sense out of reading this. Hardest part is finding something that will contact the whole bearing neatly to cool it.
