- Earmuff hearing protection. It's important that the cans are deep enough to hold speakers and the battery; I chose the 3M Peltor 105 (~$20); they provide +30dB attenuation, protecting you in up to 105dB environments.
- Over-ear bluetooth headphones. The key thing to look for here is good controls, a speaker that will fit in the cans, and quality. I chose the Kinivio BTH220 based on amazon reviews and price (~$25-30) and am really happy with them.
- Screw drivers (Kinivio requires tri-wing)
- Soldering iron
- Exacto knife
- Wire snips
- Heat-shrink tubing (optional)
- Hot glue or plastic welder
Step 1: Disassemble everything
Next, disassemble the headphones. Mine had small phillips screws holding the band together, and tri-wing screws holding the phones together. Why did this company think that it was important to keep people from opening the headphones they bought, I don't know. A security-head screwdriver bit set like this one or this one is a useful thing to have on hand anyway. (If you don't have a set and are itching to open your headphones, you could just use a rotary tool to grind through the three screw posts.)
Make a note (or photo) of which wires go to what.
Finally, use an exacto knife to cut through the glue that's holding the speakers to the grill, and use a small flat-head screwdriver to pry the speakers off. Go slow!