Now we have to figure out how we want to wire out pedal for power and bypass. The Off-Board wiring
PDF has 6 different wiring setups depending on what you are after. If you can only find a DPDT switch you will have to use one of the schematics with the Millennium By-Pass setups which requires extra parts and a separate board which will eat up more space.
The Quickest and Easiest route is to get a 3 pole double throw switch (3PDT) from Ebay (the cheapest) or other guitar part sites on the web. With a 3PDT switch you can wire a LED without the hassle of adding a separate circuit board with the ByPass circuit. We will be using the Offboard Wiring 5 scheme for this project. This setup will allow for an LED, battery power, and for external 9V DC power.
Determine the best spot on your case for the input and output jacks. I like them in the back to keep the guitar cables out of my way when playing and for this case design it provided me with the most internal space. Use a spring loaded punch to mark the center of the holes, this will give you a center and will keep the drill bit from sliding around as you drill. Drill out these holes and also the holes for the 3PDT stomp switch, the 3 Pots, LED, and External power connector. You can build a cardboard mock-up of your case and play around with the placement of the parts before your drill if you are unsure of the fit. I used some thin gauge sheet metal to fabricate a bracket for the PCB mount that connects to the case via the center pot in order to not have to add any more holes in the case.
Now we solder all the wires to the jacks, switches, and power connectors as laid out in the diagram. Double check all the runs to make sure they are correct since it is easy to mix up wires in all this chaos. I temporarily mounted everything in the case to get an idea of the length of wires I will need to solder all the jacks and switches together.
Once the distances where measured and the wires were cut I took everything apart and soldered it together. I left the wires running to the 3PDT switch a bit long as to give myself some room to run them off to the sides in order to have room for the battery clip in between the board and the switch.
I used a thin piece of plastic to separate the battery from the exposed circuit board traces to protect from any short circuits in case they happen to touch each other.The plastic is bent like the circuit board attachment bracket and connects to the case using the holes drilled for the battery clip which is mounted to the bottom of the case.