This is a reprint from my website, but not everybody gets over there, and I think many places don't have enough detail to do this topic justice. You can check it out here.
So, first off, here are the parts for a Velocity brake. Note you shouldn't need a disk, a pressure plate, or a backing plate. I have the disc because we gouged it with the rivet. I'm going to spare a pressure plate and backing plate in case I screw up the rivet holes.
Part No. Part Cost Spruce Part
66-105 Organic Lining $ 13.75/each 66-105
063-01100 Pressure Plate $ 56.75/each 06-01208
164-01501 Brake Disk $ 171.75/each 164-5A
064-01500 Backing Plate $ 97.65/each 064-01500
Basically you fix the tool into the vise. There are 3 attachments for it. One is the "anvil" - these are not the real names, which I'm not sure of, but this is for your understanding. You leave it out to remove the old rivets. You place the part in the too with the rivet head facing this bottom hole in the tool, then take the punch that comes with the tool, and a ball-peen hammer, and give it 2-3 good raps until the rivet rockets out of the bottom of the tool. Then get the other rivet out....
Next, get the new pad. It comes with rivets, place the rivet in the pad... head goes towards the disk... Put the anvil in the tool, then get the "setting punch" which has a divet in it, and a curved profile to bend the rivet over. Set the head of the rivet on the anvil, and center the set on the new rivet. Again, 2-3 good raps with the hammer, and check that the pad doesn't move (much, just enough to get the other rivet in). Now repeat with the second rivet. Voila'. You're done. Really, if you have the right tool, this is a 5 minute job.