Led headlight retrofit

Has anyone tried modifying this headlight to use a cree xml emitter with dual 14500 batteries and possibly a planer convex lens ?

For 3 bucks I was thinking of trying on the challenge.

http://www.harborfreight.com/headlamp-with-swivel-lens-45807.html

Keep in mind that it’s all plastic, and even if you built a nice fat heatsink for it, you wouldn’t be able to drive it hard. Plus, protected 14500 are unlikely to fit.

Darn i was all excited, maybe i can just use the strap and rig up something