Here is what I would do, based on the drawings . . .
Set the dish so the face is vertical. Use an inclinometer to make sure! Use the side brace mount holes as the "center" of the dish. Put a tight string across the dish, from one side brace hole to the other. The string will obviously not be against the dish surface. Take a broomhandle and cut/mark it to 1.10 meters Put one end against the dish, under the center of the string. Take an inclinometer, and set it on the broomhandle. Tilt your broomhandle down 23º , and where the end of it is, that's where you want to put the LNB. This should get you quite close.
From here you tune as you would on any dish, by adjusting the LNB toward and away from the dish.
edit: If you have the mount shown, check the elevation of a known satellite against the marks on the mount. Adjust the height of the LNB to agree with the markings. You should not be off by much if the above procedure worked and you followed it carefully.