But at least we know we'll be waterproof, no more rot like this
First, you need to CLEAN the floor (or whatever surface you're putting it on) so there is no debris, dust, or dirt
Next, measure out the space, roll out the kerdi, and cut your sheets
We clearly cut ours big - to be safe of course.
Next, apply a thin layer of thinset
And lay the kerdi down on top
It's important after you've laid it down to really work at smoothing it all out, getting the bubbles out and other imperfections so it's all nice and flat. Otherwise, your when you lay your tile it'll look like crap.
We had our pieces run up onto the wall a bit as well (you can see on the left in the above pic), just to make sure that water didn't collect in the corners (an often forgotten about place, but VERY important).