Jan 24, 2020
Need some help here - didn't expect a "kit" project for a flashlight. Received mine today, unscrewed the cap and all of the components below popped out. No idea what the correct order is. Plus, the clip on the cap is a HORRIBLE design. I had to bend it back just to be able to attempt to screw the cap back on.

Feb 6, 2020
2 problems, most lights like this are designed to be accessed from the head (FW3A). The second problem is when you unscrewed it like this there is a brass retainer piece that is stuck up inside the cap now that keeps everything in place when the very tail cap is removed. This is what the tail clip rides on. So to reassemble I would separate the brass spacer from the very tail cap then the following. Washer, Switch, plastic spacer with the longer parts facing the switch, Rubber boot on the top of the flat then the brass locking nut. I use tweezers or piece of metal bar to lock this in place. The chrome button assembly is pretty self explanatory when you get it apart. I have taken apart and reassembled upwards of probably 50 of these so if you need help let me know or join the Reylight Facebook group for more help.
Mar 1, 2020
assemble order is: put the copper washer into the tail, then switch- plastic part- rubber cap, finally screw the tail.

Oct 18, 2020
Well today the flashlight is headed to the trash. Doing a regular battery replacement I had TWO Mexican Jumping Beane vents with the overly complicated switch assembly. Resulted in 25+ minutes of wasted time and the brass washed disappearing somewhere on in the room. Hate to leave a 1 star review but honestly I'd give it 0 if possible. The design of this light makes it useless anywhere but in an indoor, office space - but even then you're prone to what happened to me. I couldn't imagine using this outdoors (or God forbid in a situation where it's really needed) and have to open up that Pandora's box of a switch.
Dec 22, 2020
Why didn't you just take the head off to switch the battery like the other person suggested?