3KS can look really overwhemling but it's really not so complicated when you get down to it.

There are 6 sliders on the right and 6 sliders on the left of the keyway interfacing with two sidebars. There are cuts on the edge of the key but they only interact with a passive sidebar.

The basic idea is to just use a little hook or a custom tool if you feel the need (I did just fine with an ssdev short hook) to slide all the sliders around one side at a time. The most difficult part is getting your bearings in there and only moving the one slider you want.
A backlight or fiber optic light down the keyway help, looking down the keyway to see where everything is can be very helpful for this lock but it's not required.

The 3KS doesn't punish you for picking out of order, you can release tension and friction will keep all the sliders exactly where you left them.
The sidebars will start to poke into the keyway as you pick, and there's sliders right up in the front, so remember to keep your tension wrench out of the way. I used a regular Peterson prybar on mine.

Start off with heavy tension. Usually one side will bind first. Go around feeling for bound sliders and they'll give you a fat click into place. eventually you'll get a false set, and then you'll need to feel around on that side for sliders in false gates. 

Feeling for false gates can actually be done two ways on this lock: if the slider is binding, it will be totally locked up while you have tension applied. However, you can also tell by wiggling it. False gates are narrower than true gates, so even if the slider isn't binding yet you can sometimes tell that's it's in a false gate beforehand.
Release tension until the slider you suspect is in a false gate is free, then move it someplace else-- very carefully so as not to disturb your other sliders.
False gates are always right next to the real gates, so you won't have to move the slider far to get it out. Check just above and below the false gate, one of them is bound to be the right spot. 

After everything on the first side is set, you just repeat on the second side. While you're picking on the second side the first side will *probaby* remain locked in place by the sidebar and you won't have to worry about accidently bumping it, but YMMV depending on tolerances. 
If your 3KS doesn't isolate the sides you'll just have to wing it.

Progging is optional, you could probably get it without it but the lock is definitely overwhelming when you start it out. I recommend starting at 6 sliders (either one side alone or the front 3 of each side, up to you).
To gut it, remove the circlip (or whatever else), insert and remove the key to line all the sliders to the center, then the plug should slide out with some wiggling. If you get anything out of order, remember the 2-pronged and 1-pronged sliders are arranged in a checkerboard kind of way:

: -
- :
: -
- :
: -
- :

The bible has no moving parts so no need for followers or worrying about anything in there. The full part list of the plug is:
- 6x 1-prong sliders
- 6x 2-prong sliders
- Left sidebar
- Right sidebar
- 4x active sidebar springs
- Passive key sidebar

Also, don't turn the plug 180 or 90 degrees in any direction or you'll risk one (or both) sidebars springing out and getting wedged in a weird spot.