Bend the leads on the LED down flat to the bottle cap. Here's where I should have soldered, and probably will eventually. I was just eager to put this together to see what it looked like. Also, I'll add a switch, so I don't have to keep taking out the battery to shut this thing off. Again, I was lucky in the fit of the bottle cap in the eye cup, didn't even have to tape them in. Your mileage my vary.