Bearing can be removed by tapping around the inner race with a drift and a hammer. Use brass if you can, to avoid dinging the shaft. When off, clean the shaft well and check closely for dings from the drift. You can polist any down with a fine file a a little patience. Just like any bearing race stuck on a shaft.

FYI - never mate aluminum with steel / iron w/o something to separate them, like a teflon shim. Aluminum will ionically deteriorate unless it is of a special alloy. Especially for salty areas. Try an experiment - bolt a couple of scraps together and see what happens over time....