I think you may have to contact Apple. This is what I got when I googled your question.
I called too at Apple. They only do one to one exchange. They don't do any servicing. The price is just near new retail price. Mine is still working fine, only need to change the head band as its already worn out over last 3 years. No such firm doing such head phone repairs??? Saw a you tube video on how to dismantle Dr Dre Pro but the procedure is very complicated with soldering involved and the wiring, parts, components need to take out and put back are too technical. Any wrong step will spoil the whole set. So trying to find a place willing to change the head band. Don't mind paying for workmanship and parts. Rather than paying for a brand new one that will set me back another over 400 sgd.
Only Sennheiser has a comprehensive spares department that can replace individual components..
Nikon D750; FM2; FG; 55mm Micro Nikkor; 28-300 VR; 70-200 VR; Nikon V1 + 10-30mm
FB: Hilos Camera Repair
Can you do it for me? I bought the replacement head cushion. There is nothing wrong with the headphone but the head band and ear cushion are worn out. Please help. sms me 81259563