i struggled to open my one yesterday used rubber gloves to grip the head and body the unscrew
the LED screws out of the head on a brass pill as you look down the are 2 small indentations use tweezers or long nose pliers to unscrew it screws away from the lens
Strap wrenches? The things you get to open recalcitrant jars and bottles. One on the head and one on the body. Matt didn't seem to have any trouble getting his one apart. http://budgetlightforum.cz.cc/node/1123
If you have separated the head and body, most lights look something like this inside the head. This one gets unscrewed by using circlip pliers or a haemostat on the solder blobs. Some have notches in the pill to help unscrewing them. If you are very unlucky, the pill can be glued into the head though I've never seen this myself.