Step 5: Final assembly
Press in the LED holder assembly into the lower half of the ring. The best way I've found to do this is the set it LED side down on a flat surface, position the lower ring section over it and then gently press down. You want it to be flush with the inside bottom of the ring. Now the top of the ring can be glued into place with a couple of tiny dabs of hot glue using a glue gun. You don't want to use a lot as you want to be able to remove the top of the ring should you ever have to replace the LED.
Note that there isn't a switch (and there really isn't room for one- I tried) - if the battery is in then the ring is on. By bending the contact wire I have been able to get the ring to turn on when I'm wearing it but it's a lot of trial and error and not terribly reliable. As for run time I have run one of these for 36 hours straight- at that point there was noticeable dimming of the LED. In a dark room this thing is very bright.
That's it- you're done! Now put your ring on, take your Green Lantern oath and join the Corps!