11.) Your plate will probably be pretty ugly, something like the picture below. To clean it up, just use your sandpaper to remove the corrosion, the spry them off with the contact cleaner and use a little bit of vasoline on a piece of paper towel or cloth to clean the dust and residue off of the plate. Don't leave gobs on there, but a thin layer is ok.
12.) Now remove the rotating assembly from the body. Carefully pry around the edges, and like the dimmer insert, be very careful of the circled area. It also has a spring and a ball bearing that will jump out and get lost if you're not careful.
13.) Remove the copper brushes from the rotating assembly. Be careful of the springs that hold them in, and try to keep them bent in the same shape (they should be bent slightly towards each other to grab the catches in the assembly itself). Sand the tips down, and spray them down with contact cleaner to remove any corrosion and residue. After cleaning, wipe them down with the vasoline and leave a very thin layer on them.
At this time, you can remove the entire PCB if you wish. The points that you need to remove are as follows:
I would only recommend this if you suspect a bad trace or cold solder joints. I did it when I rebuilt this switch just to check things out, and found no real problems. A good spray down with contact cleaner may be a good idea to clear and residues or corrosion from the joints.
Now you can begin re-assembly.
1.) Pull the springs for the brushes out a little bit, then but a bit of grease on the tip, and insert it into the assembly while twisting. Push the brush into the assembly, makeing sure that the little point on the bottom goes into the spring, and that the brush snaps in and doesn't fly out. Push the spring a couple of times to make sure it doesn't stick.
2.) Lube up the chamber that the rotating assembly sits in, then pull the spring for the rotating assembly out a slight bit, then put a bit of grease on the tip, and insert that tip into the assembly while twisting to spread the lubrication. Push the ball into the assembly on top of the spring, and carefully put the whole unit back into the switch body. Be careful not to lose control of the ball and spring, and rotate the assembly to the full down position that it was in when you removed it. Push it in gently to make sure it's fully seated.
3.) Use your soldering iron to spread any remaing solder on the "spikes."
4.) Push the back plate back in, making sure it is properly seated.
5.) Push the white insert back in behind the back plate and make sure it snaps into place on all sides.
6.) Put a chunk of lube on the spring for the dimmer rotating thing, push it into the black piece and put the ball in after the spring, then push it back into it's place in the white insert, making sure that it's in the lowest position.
7.) Clean the spikes on the brown PCB so that they will slip through the plastic insert and PCB on the other side.
8.) Carefully push the spikes through the insert, then push the rest of the PCB down into the insert, makeing sure the spike coming up from the switch back plate goes through it as well. Also make sure the the white rotating piece on the underside matches up with the black dimmer rotating insert and it's aligned correctly (by using your sharpie mark from earlier)
9.) Solder the little spike on the brown PCB back in place.