Drill two parallel rows of six 1/16" holes each in each cap, about a quarter to a half inch apart. Fit the leads from the LEDs through the holes and dab them into place with a little hot glue on the outside surface of the cap. Make sure all the leads in one row are positive and all the leads in the other are negative. For a primer on LEDs, check out Wikipedia here: http://en.wikipedia.org/wiki/LED
Wire the leads together in a parallel circuit, i.e. two wires as the "sides" and the resistors as the "rungs" in a ladder-like formation. This distributes equal voltage to all the LEDs, as well as continuing to function even when one of the LEDs is burned out. I used speaker wire with a translucent coating that lets the copper color show, which plays well with the orange bottles.
Last, I wired it to a 6V transformer, formerly of an Aiwa discman. This steps down the house's current enough to keep the bulbs from burning out.