I want to start modding flashlights. How do I start? I want to use anduril for firmware UI and xhp70.2 led. And a hight watts driver.
Welcome to BLF LordBETOT 
You will get many suggestions here. 
What size light and type, EDC, flood, zoomie, thrower, big, small, budget, expensive ?
There are ’ Host ’ lights you can purchase cheap. You will need to buy the driver, led and batteries for it.
Example is a Convoy C8 that is cheap and easy for beginners.
You will need some tools like a soldering iron or gun, solder, small screw driver kit for starters.
There are many modders here at BLF, just give them time to see your post.
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Thank you for the warm welcome CNCman! I will check the host lights
I will list the “wants” so I can built based on it
1. EDC
2. 18650 battery as I have alot of it.
3. Budget, I guess max of $200 for the whole build as I already own the imalent ms06 which is 199.
4. Soldering iron, multi meter, etc. I already own as I hobby also with arduino
5. USB type c rechargeable
6. Water resist no depth required as I will not be using it under water.
7. Min of 4,000 lumens
8. Light distance of 500m? (Not sure if possible with cree xhp leds).
Basically I want the same FL as the emisar d4v2 but withbusb chatging and a xhp70.2 6500k bulb.
Convoy sells host versions of the M21C flashlight and L6, which are great hosts for xhp70.2’s either with a boost driver or fet driver (for L6). They do not have USB c charging and aren’t EDC though. If you want all those features, you’ll probably have to defer to a factory light with USB c charging
the shortest path to success may be to buy that light and change the LEDs, if you insist
consider the disadvantage of in light charging
you cant use the light when it is tied up as a charger
this is my preferred alternative to in light charging, that lets me use USB to charge any size cell, without disabling a light
I own lights with built in chargers, I found them less practical than the Universal Charger.
bear in mind that I do not consider it safe to leave a LiIon charging unattended. So not safe to leave a LiIon light on USB charge overnight, and certainly not constantly for days on end.
Looks like I have to let go of the charging feature and it should be ok. I also thougt it that it is too much of feature to have charging ang water proof at the same time.
its good that you are flexible
It is hard to find a light that meets all my criteria
which is why I end up with many lights, some of which meet many of my criteria
beware, I bet you cant buy just one
Totally encourage you to learn to change LEDs… Im really glad people here helped me to learn. There is great modding support on this forum.
recommend the 10x10 hotplate
pic is a link to more info