You can tap out the old races with some sort of drift (piece of round stock, long screwdriver ,or the like) Just work your way around in a circle and just move it a little at a time until you work them out.
I have a race drift made of aluminum made to drive those type races in place. You can also use a block of wood to carefully drive them in place, carefully being the most important part. You can also use a long bolt with washers to draw them in like in the picture of the tool, just be sure they don't pull on the surface that the rollers ride on.
