Maybe you can send it in to zebra. I don't think there is an easy way to get into the head.
Sorry to hear yours broke, my H51C passed the throw it at a pole test today.
I was up on the hill / bank behind my house weed-wacking / clearning brush and it got dark on me. So my GF came outside and I asked her to toss up my headlamp. She was a bit worried, and, well, shes not a great shot. I told her just trow it up as hard as you can and I will catch it. So she threw with all her might and it hit the top-rail on the fence (didn't make it over) bounced off and fell about 15 feet back into the dirt. It made a loud glass breaking sounding noise when it slammed intothhe toprail. Fortunately my one day old light survived without a scratch, I was amazed!