I thought that by the pictures you in your prior post showed the lens and cover off of your light. Looks like you had the LED MCPCB off as far as the wires allowed, as well. So I don't understand why you need more access to swap LEDS. Searching here and DIY lighte on MTBR I see no one has posted mods to either light. So it looks like you are on your own as you have no replies from someone who has.
The XR-E Q5 at 2 watts (assuming they are not counting the driver) means about 570 mA from the driver into about 3.5 Vf for about 140 lumens before losses.
An XP-G at 570 mA is about 3.12 Vf for about 1.8 Watts and 210 lumens before losses for an R5 bin.
An XM-L at 570 ma is about 2.85 Vf for about 1.65 W and 210 lumens before losses, for a T6 bin.
So a gain of 10% runtime and 50% in lumens for the XP-G R5, and a 17% increase in runtime and the same 50% increase in lumens for the XM-L. My guess is that the heat sink is good for warm nights @ 2 Watts, ridden slowly or even stopped. You might push more current and more power but it should not be more watts than the area of air cooling of the heat sink (1 sq in/watt minimum, 1.5 would be better). That will require access to remove/mod the driver or replace it, which I suspect is why you wanted to know how to disassemble it further non-destructively. A new LED and driver in a light which you admit has a poor beam suggests you should keep this light as a back up or be seen light and build a new light meeting your needs better. We all understand the desier to mod. So have at it and report back.
