Im sure you have tried but gave up when frustration kicked in. Those races are not welded in. They may be rusted but they will come out.
Fold them in on each other. Take a punch and bend it off of the inside of the swingarm. Use a small punch that will get in behind it. If you can bend it away just a little bit all the way around, then you can spray lube in there and let it sit.
Use a dremel or an angle die grinder like the photo and cut the race in half by inserting the bit into the swingarm tube and grinding down thru the race to the tube. do this on the top and bottom to make the race 2 pieces. Then use the punch to knock it loose.