There should be a part inside that has a grove cut in it allowing a "drift" to access the race. A drift is usually referred to as a hardened round piece of metal. Get a BIG hammer and whale on it. Watch the fingers. You can use lock grip pliers to keep your fingers away. There is a special tool for that purpose too. Also make sure to support the bottom edge leaving the bearing race space to fall out.
The drift I use is longer than these but you get the point.
Bearing races are never fine to reuse, unless you are reusing the bearings too.
I do not recommend using a chisel like this guy does as a drift is the proper tool. Note this is for tapered wheel bearings.