I would like to put a Nichia 219 in It.Can I reflow a Nichia 219 on to a XP-E board? Does this come apart at the red arrow by unscrewing counter clockwise?
Unless you got lucky and the factory forgot to glue yours, they are usually impossible to losten without destroying them. Here’s one on the similar ITP EOS A3
torch?
J)
If you can get it apart you can reflow the Nichia right onto the original mcpcb. Good luck getting it apart though. I wish I could offer some good advise there but I know its been done by others and I'm sure they'll chime in to help. ;)
I saw one post where the guy put the head in a plastic bag in boiling water to free up the adhesive. Also, the innards are apparently potted in silicone…
If it’s potted in silicone you can try silicone sealant remover.
My Maratac copper AAA did not have a glued in pill, came out just fine (I am sorry to say mine does have a 219 in it now, reflowed on the original mcpcb). The copper AA version was a different story, totally siliconed-in pill. Got it out finally, but barely left the light/electronics intact doing that (bench vice, blowtorch, lengthy brute force with pliers, first got it smoking hot then mm by mm it gave way, had to struggle all the way out, even once the pill went it took me an hour to have it finally out.
good luck! 
Does the head come apart at the red arrow?
why are you sorry its a 219 now ozz?
My maratac AAA quit working a few monts ago when I attached it to dog collar while camping, I have tried everything to take it apart. Nothing helped, heating didn’t loose it up, freezing did nothing - I give up. But a few weeks ago I decided to give it another try. I heated it with a lighter and then glad froze it in a cup of ice. Repeated the process about 15-20 times. Then the pill came out without a glitch. The inductor on the driver was broken off. Replaced the driver and reflows an XPG R5 on it and installed an Arokay driver in it. Now it is as bright as it gets. It draws about 1,4 AMPs form AAA Eneloop. Try the heat and freeze repedetly, worked for me.
From the second picture it looks like the knurled part threads into the Maratac collar. As Chloe says try some silicon caulk remover(hardware store) on the inside first. If it doesn’t harm the ano but does soften the adhesive, clean and reapply inside and out. Do that a few times then wrap the two parts with rubber tubing and twist. 50/50 bs but you asked. If you have a soft jaw vise and a small strap wrench that might help
the sorry-part was that fatboy has not succeeded yet while I had such an easy job doing the swap. I am not sorry having the 219 in it though, it is perfect in these AAA lights, especially with 10440's (I have an Efest IMR 10440 in it now).
I put a Nichia 219 in mine. Output went down quite a bit more than I was expecting… from around 90 lumens down to 60 lumens… but I like quality much better than quantity in my lights.