Step 3: The Scary Part
Unfortunately, I didn't take any pics of the process. But I used a combination of a 4" putty knife, a plastic gasket scraper, and the chisel to gently, GENTLY pry the molding off. If your baseboards are painted, you'll probably have a harder time, since you'll have to remove caulk, and re-caulk it (and caulk and touch up paint on nail holes, if you're picky) once the project is otherwise completed.
If they don't want to come off, DO NOT FORCE IT. It will most certainly crack. Find the stubborn nail, and use a nail set to hammer it through the board, into the wall. Label the backs of your shoe molding and baseboard, to make it easier when re-installing.
After they're removed, this is a good time to clean all the dust off, and find whatever slipped between the boards and the walls over the years. I found a penny!