EDIT: I can't find any pics online so if i have time tomorrow i may hit the junk yard and buy a caliper and tear it apart and take some pics to post so everyone can see how they work.
hell if you can find a few sets.. you could make yourself some money...
you can buy them from napa.... they charge you a core if you dont have any... but even the replacements dont come with the springs or levers!!!!! so they are hard to find!!!!!!!!!!