We'll stack the two NeoPixel rings with the smaller ring on top, and nestle the battery inside the larger ring.  The gemma will sit on the back of the assembly, so the on/off switch, USB port and battery port are accessible.  

Wiring Connections

The Assembly page will show step-by-step wiring. Here is a table of the connections that will be made:

For the capacitive touch pad to work when it's connected to your pendant, you'll need to be sure to use a pendant that conducts electricity.  Use your multimeter to test and be sure your pendant is conductive.

If your pendant doesn't conduct electricity you can still make this work.  Instead of touching the face of the necklace to change colors, you'll just need to flip it over and touch the gemma's capacitive touch pad directly.