If you're not replacing the rotors, I hammer the old races out using a drift (I've also knocked them out and installed the new ones with a 3/8's ratchet extension in a pinch). I don't believe in reusing the old races, especially if the bearings are well past it, which yours are. The easiest way to install the races is to borrow a bearing/seal installer kit from a local auto parts store. I like to leave the races in the freezer overnight to shrink them a tiny bit. You'll be able to feel/hear when they're fully seated in the rotor.
I look at it this way... If using the old races was a good idea, then why do new bearings come with new races? If it was usually okay to reuse the old race I'd think they'd sell them separately.
Bearing Race/Seal driver kit: