Yep, that's all there is to it. Once it's apart, check the cups and the spindle races for pitting. The surfaces should be smooth since if they are pitted, the bearing won't roll smoothly. How smooth they need to be depends on how much you care about smoothness. My guess is that the grease is dried up and a thorough cleaning and re-greasing will be sufficient. As long as you have it apart, you might as well replace the bearings as they are cheap. They'll probably be in a retainer so just push the old ones out and push new ones in.

You should be able to find new bearings at your LBS or on-line. If you need to replace the spindle you can ask around your LBS to see if they have a box full of old ones. If that doesn't work I'd try looking for one here at BF. Hopefully you can just clean it up and re-grease it and go.