The domes feature four mounting tabs with cavities. These are designed to fit neodymium magnets discs – (D41 - 1/4" dia 1/16" thick). These can be super glued to the tabs but it's super important the polarities match across the two domes. Marking the north and south poles are a good method. I kept track of the polarities while placing by hand holding a stack – Use your preferred method!
Install Dome Framing
The pixel core roller assemblies are secured inside the domes. Place one of the cores inside one of the domes and line up the mounting tabs with the holes on the framing. Insert and fasten M3 x 10mm flat head machine screws through the tabs. Hold the framing in place while fastening the screws. Repeat this process for the remaining tabs and proceed to setup the second dome.
With both domes setup with the pixel core assembles, it's a good idea to test out the neopixel strips. To do this, I plugged in the first strip to the Prop-Maker FeatherWing and ran a neopixel strandtest. This way we can see if there's any dead pixels (fingers crossed) and if our pixel arrangement is how we want it. I must have rearranged the two at least a dozen times, so don't be too upset if you need to take it apart ;-)