Trying to setup my new Starla. However, the stoptail is in two pieces and they both have adjustable heights.

Which piece is supposed to adjust the action?
What is the proper angle between the piece that it closest to the pickups and the piece that anchors the strings?

In other words, how am I supposed to adjust action on this thing? Using the intonation bridge part or the anchor part? If the answer is the anchor part, then how tight are the strings supposed to be across the intonation bridge?