Don’t forget to wrap the tweezer handle with a thick cloth. Will make it easier to turn.
Mine was a pain to get the driver ring loose, I ended having to hook a flat tip screwdriver into one of the holes on the ring and really hork down on trying to spin it, once it popped loose it is easy to take in and out
Fairly easy with needle-nose pliers from Harbor Freight. I bought a bunch when they were on sale for $1.29.
http://www.harborfreight.com/5-3-4-quarter-inch-needle-nose-pliers-40696.html
Naturally you have to pick through the bin at the store, some are ground finer than others, some are rounder some are squarer.
No horking required. 
but…but…but I like to hork 
But you wouldn't enjoy it as much if it was required.
What is “hork”?
He followed me home. Can I keep him?
Only if you can afford to keep him. Hork's have a very expensive cost associated with them.
this is true, Here at the School of Vet Medicine, Horks will get there own special pin and have to be kept away from other animals as they are very aggresive. If you are lucky enough to find an water bound Hork and if you decide to keep him/her, they will need alot of attention as they are very social animals.
It just unscrews. You’ll need something to put into the dimples. Some people use tweezers, but circlip pliers work just as well.
The retaining ring on these F13’s is glued or torqued very tight, so undoing it first time is difficult, but just needs some elbow grease.
aka “the hork” 
I got my nose plier and finnaly managed open it and to move the + to the other + , now its better but not better than my Convoy c8 at stock,
do you think the F13, with a 3A driver ( + 0.380mah*2 ) can handle 3.8A without problems ( of course with a good 26650 ) ?
It can handle 3.8A no problem.
Thanx for the fast reply .
So its ok for 3.8A what about 4.1A or 4.5A ? and should i add some thermal paste behind the led ?
Is the GB still active?
No, and the code do not work anymore 
Just got mine. Ordered 7/8. Took over 5 weeks.