Here's a few tips I would give you:
1) place the board in the ecan and check for clearance on the battery contact side. You don't want any of those holes near the edge of the ecan (espcically with the downboy). Mark the locations of the three sets of holes and file some of the metal away if necessary. I always file the area around the Vin+ hole, if nothing else. Sometimes the LED+ holes are far enough away to not worry about, but that's with the badboy - the downboy holes are further out IIRC.
2) solder the lead wires to the driver board. If you pre-tin them well, just a quick touch with the iron will secure them in the holes on the board. Make sure your wires are long enough before you do this! You can trim them down later, so too long is better than too short.
2) after you have the wires soldered to the board, glue the driver into the ecan. I just put a thin line of regular superglue on the inside lip of the ecan and drop the board in. Make sure you line up with the areas you filed down. Don't use too much glue, you only need to hold the board down for a bit until you goop in the real potting material.
3) solder the ground wire to the hole in the upper edge of the ecan. If you got one of the ecans without the hole, just file a little groove in the top lip and solder into that groove. trim the wire on the outside and file it down until it's flush.
4) Test the circuit out. I generally hold the ecan in a vise with the lead wires paralell to the ground, then press an old beat up luxeon to the ends of the leads. I then power the circuit with 2xAA in a radio shack battery holder (just touch the wires to the battery contact and edge of the ecan). If it lights up, you're good to go. I usually give the real emitter a quick direct drive 2xAA test here as well.
5) test fit the assembly together. put the ecan in the head, drop the PR board over the leads, fold the leads down, plop the emitter into place. Go ahead and gently fold the emitter leads up a bit so you can slide the lead wires under them when you assemble. I also trim about half of the big part of the emitter leads off so there's no chance of them shorting against the inside of the head, but there's still enough left to solder down to the PR board and secure the wires. Take everything out (trim the leads if needed) and re-test.
6) mix up the potting bog. I use AA, I'm not familiar with 2ton. Nailpolish on the emitter slug isn't necessary if you use a good non-conductive epoxy like AA and you have an anodized head. you have to work fairly quickly from here on so the epoxy doesn't get too thick on you.
7) pot the ecan. you don't need to fill the can up, just use enough to cover the bottom. Make sure it covers the edge of the board, as that is what will keep the driver in place.
8) put a little bit of epoxy inside the head where the ecan will go. Not too much. I generally put a dab at the 12:00 and 6:00 positions (assuming the lead wire holes are at 3:00 and 9:00).
9) flip the head over. it's good to set it down on your workbench here so the can doesn't fall out while the epoxy is curing. sometimes I screw an empty CNC-123 battery tube into the head to make sure the ecan doesn't move. This also makes the piece easier to hold while working on it. Dab some epoxy in the middle of the head where the emitter will go. Don't use too much, just a thin layer will do. add a little extra away from the center to hold the board down. Drop the PR board into place and press it down. carefully drop the emitter into the center of the board - be careful that you don't have any epoxy on your fingers! put the reflector in place to check for emitter centering and (gently but firmly) adjust with your fingers if needed. DO NOT SCREW THE BEZEL DOWN, it will rotate the reflector, which will rotate the emitter and you'll be in big trouble. at this point, I usually clamp everything down with a small quick-grip clamp and let the epoxy dry for about 30 minutes. You can do a post-cure in a toaster oven, but I don't do that any more.
10) remove the reflector. slide the lead wires under the emitter leads, push the emitter leads down, and solder. Just a tiny bit of solder is more than enough. you want to keep this joint as tidy as possible so it doesn't short against the reflector. Test the head (without the reflector in place). assuming it works, cover the joint with nail polish and let that dry. put the reflector in place, screw the bezel down. remove the bezel and reflector and check the nail polish. repeat a few times. If none of the polish has rubbed off, you're in good shape. Put everything together and test it out. If the reflector is rubbing the polish off, you need to remove the polish and re-solder the leads.
