First I made sure the fuselage was level and then using a level with a 3 inch block on the level as per Van's instructions made sure the wings were level. They are as close as I can get even using my digital level they are within 0.1", pretty good. Drilled the holes at the back and the tank attach on the front, wings attached. Mounted the ailerons and the flaps and the flaps need to be filed/trimmed where they meet the fuselage. Connected the moving surfaces to the control stick, all works as it should.