Before embarking on this adventure, I did a web search to see if anyone had taken these hats apart to understand what the components looked like before shelling out $50 for two of them. One such link existed with a thorough tear-down and exploration which proved helpful enough to forge ahead. Here's maker Andy's link: http://stuffandymakes.com/2012/07/08/disney-glow-...
You can purchase the Glow with the Show
Mickey Ears at Disneyland and Disney World, or via their park merchandise sales at 877-560-6477, where I purchased two.
The process begins by ripping out the inner foam insert which is glued into place inside the hat which protects the electronics which are connected to an arched plastic band. Carefully pry open the two-piece plastic ears exposing the flexible PCB that runs through the hat and has the lights and other electronics attached. You will need a small screwdriver to complete the removal of the ears, and it's fairly likely that this will destroy the ears in the process, but you're making something at least as cool in their place! Make note of where the wires connecting to the battery compartment are so that you can ensure correct relocation. Using a soldering iron, heat and remove the wire connections from the battery compartment. Using a hacksaw or grinder tool, remove the batttery compartment screw holder and the plastic band on either side of the battery compartment. This will leave you with a simple rectangular battery 3 AAA battery compartment. Repeat for both ears.