Things You'll Need
Instructions
Locate the adapter bolt inside the adapter, and have the Allen wrench that came with your Darth Maul FX lightsaber at the ready. Unscrew the adapter bolt one turn so that the halves of the adapter are able to rotate freely.
Take one of the Force FX lightsabers and remove the battery end cap. Replace with the supplied adapter, ensuring the adapter bolt head is exposed. Tighten until secure.
Take the second Force FX lightsaber and remove the battery end cap. Attach this second lightsaber to the adapter you attached to the first lightsaber by holding the second lightsaber securely and rotating the loose half of the adapter clockwise.
Line up the red and silver knobs on the two lightsabers by rotating the two lightsabers about the adapter, pulling apart the two halves of the adapter to disengage the indexing ribs.
Unscrew and remove the second lightsaber to expose the adapter bolt again -- do so with one hand holding the two halves of the adapter together. While still securely holding the two halves of the adapter, tighten the adapter bolt with the hex key, being careful not to overtighten. Once the adapter bolt is tightened, reattach the second lightsaber.