Will do.I took mine apart, but it was a long time ago. IIRC, both the front and back unscrew. Get some molegrips on the rings and see if you can unscrew them.
If you use tie wraps instead of robber bands you can have a Permiant mount.They were one of the first lights that could run directly from the battery and give enough light for most circumstances. I still like that one, but my favourite is now this one, though you have the inconvenience of having to keep taking it off every time you park your bike.
http://www.ebay.co.uk/itm/3000LM-CREE-XM-L2-LED-Headlight-Front-Bike-Bicycle-HeadLamp-Head-Light-18650-SET-/151628782015?var=&hash=item234dc799bf:m:m3z0uVQHEetlCJ_RNthhqcg
I rarely use my bike in the dark now, so that's not a problem for me. If I were in your situation, I'd still be using that same light that you have.