It's pretty straight forward. First you have to remove the spur gear and slipper assembly. To do that just take the small nut that's in the center of the spur gear off. There will be a series of springs and washers under it so be careful not to lose any, and lay them out in the right order so replacing them will be easier.
Then you can pull the spur gear off. Also, the slipper plates and slipper pad should come right off, too. Then you'll have to remove the silver bracket that holds the linkage and pad on. 2 screws on top. 2 screws underneath, I think. Once that's off, the brake pad and brake disc are accessible for changing.