Mod a Myo XP Belt to be regulated

Hi,
I'm new, and not very experimented in the flashlight mod! Can you help me?
I would like to change the circuit board of the myo XP belt by this: http://www.dealextreme.com/p/5-mode-1000ma-7135-circuit-board-for-cree-and-ssc-emitters-6190
And put a XM-L or XP-G DEL on. But I don't know how I have to do! Where can I put the on/off switch? And is it possible? Can you help me?
Thanks
Florent

For a driver like that, the on/off/change-level switch would be between the battery and the driver, connecting or disconnecting power to turn the light on or off, and to change the power level.

If the switch was open (no connection to the battery), the light would be off.
If the switch was closed, the light would be on at some power level.
To change power levels, the switch would be opened and then closed again, temporarily disconnecting power.

That means you would need a switch which could stay open (to turn the light off) and which could also stay closed (to allow the light to run.
If the switch was a pushbutton switch, it might be described (in English) as being 'push on/push off', but could be described many other ways as well

A switch described (in English) as being 'momentary action' would be the wrong kind of switch.

I don't know how a suitable switch might be described in other languages - even in English there are multiple ways of describing the same thing when it comes to switches, which can be potentially confusing.