Here is one of three offset-brake wrenches. Just ahead of the anchor-bolt after it goes through the frame and is approaching the actual body of the brake - you should find a part of the bolt that has a flat-area in the vertical. These fit this and you can rotate the entire brake into proper alignment. Using a cone-wrench works perfectly as well - if you have the clearance to deploy one.
http://www.parktool.com/products/det...=14&item=OBW-3
This OBW-3 also has a spanner to rotate the body by it's spring. This used to be done with a hammer-to-the-springs.
<EDIT> removing the brake is, obviously, unnecessary - though the Park photograph leaves room for confusion.