Glue the bulkheads B2 and B3 perpendicular to one of the fuselage sides of one of the booms. Glue the other side to the bulkheads. Squeze the two sides a bit at the front and glue bulkhead B1. Squeze the far rear of the sides together and glue. Use a suitable size depron sheet and glue it to the bottom edge of the fuselage sides. Remove excess material with a sharp knife. Likewise glue pieces of depron to the top of the fuselage. Make sure to leave space for the wing.
Use a pen to mark the position of the booms on the wing. Place both booms on a flat suface and keep them fixed with lead weights or a heavy book. Place the wing on top of the two booms and space the booms apart until they are perfectly alined with the marks on the wing. Make sure the distance between the center of the booms are the same both at the front and at the rear. Also make sure the distance from the right rear boom to the right wing tip is the same at the left side. When you are absolutely sure everything is lined up perfectly glue the wing and booms.
Use similar blocks of wood to raise the wing and booms from the building surface. The bottom surface of the wing should be parallel to the building surface. Put a couple of sand bags on top of the wings to secure it. Now the horizontal stabilizer needs to be placed between the vertical stabilizers at the right height. Use the same method as with the wing using blocks of wood to raise the horizontal stab and keeping it parallel to the building surface. When satisfied glue the horizontal stab.
Bevel the elevator and mount it to the horizontal stab with hinge tape. Mount a control horn at the center position.
Install the elevator servo in the rear part of the fuse and use a 2mm carbon rod as a connector to the elevator.
Install the rest of the radio equipment and two motors with 6x4 props.
Balance the plane at the CG spot indicated on the drawing and go flying.