Ooh, you did it now!
This video is in German, but see if you can follow along:
Basically:
Clear o-rings get pressed into the grooves inside the tank body (top and bottom of windows). If there are o-rings in place already, it'll be impossible to get more in there. So if you're having any difficulty, make sure there aren't any already in place. Just start on one section and inch your way around until it's all in. Then do the same for the other one.
Carefully slide the tank in there as far as it'll go, without dislodging the o-rings.
Screw the chimney into the tank body. Tighten with included allen key. I wrapped the threads on mine with a little teflon tape, but not all of them leaked without intervention.
Test for leaks: hold the tank body upside-down, fill with water, and set it on a paper towel. Leak out of the drip tip hole = leaky chimney threads. Leak out of the triangles = dislodged o-rings.
Never take it apart again!
Yikes, now the deck:
Before you start, make sure there's no gunk or anodizing on any of the threads. Check the tops and bottoms of the posts, and where they screw into. Screw in and out of them multiple times, or have at it with a wire brush.
Wiggle the bottom plate into the base.
Screw the negative post into the base, through the hole on the plate. Tighten with pliers, but be very careful not to squeeze and distort the top threads or bend the post. (maybe screw the screw into it first)
Press-fit your preferred deck over the plate. Make sure there's an o-ring around the inner circumference of the base to secure the deck. Push it in as far as you can. The posts should protrude by a hair.
Screw in the 510 pin. This connects to the bottom plate. I dunno what kind of insulator is in yours, but I had to put a KFL 510 insulator in mine to keep the pin from going too far in and wobbling. Some people have modded the little white grommet from Kanger heads to fit in there. If all you have is a tiny little 2mm o-ring around the screw, you'll more than likely have to put something else in there to secure the pin a little better. You wanna feel a little torque when you tighten it.
Press in the airflow ring.
Make sure there's a black o-ring along the base at the threads where the tank body screws on.
Word of warning: if you got one with large-headed post screws that go all the way out to the edge of the deck, you'll scratch the lip in the chimney, causing shorts and leaving you with exposed raw aluminum. So make sure the screw heads are small enough to clear that lip.
Post screws are M3 x 4; positive pin is M3 x 15, but M3 x 16 is ideal. But you'd have to grind the heads smaller to use generic screws.
Good luck. Post here if you get stuck.