The pictured RP80 is an early production piece, some details such as buckles and has changed since then but the assembly is done exactly as described in this tutorial.
Do not tighten the turnbuckle yet at this point, that will be done after height adjustment.
Attach the shoulder harness load lifters (1 and 2) to the frame (B).
The RP80 carry system is adjustable for users from 160 up to 200 cm tall.
To adjust the back length you move the shoulder harness assembly up or down by adjusting the wide attachment/adjustment strap (1).
By attaching the shoulder harness attachment/adjustment strap to the frame's lowest horizontal support pipe (A2) instead of the middle support pipe (A1) you can adjust the back length down to the minimum recommended user height of 160 cm.
Move the metal buckles (2) on top of the shoulder harness so that they are centered on top of the center of your shoulders or a little bit towards your back. This is very important for the shoulder harness to fit properly!
Lift the assembled frame onto your back and try it on. You want the shoulder padding to wrap neatly around your shoulders so that there are no gaps between your back and the padding. When you have found the correct height adjustment tighten the turnbuckle.
Attach the pack bag's bottom straps (1 and 2) to the frame's (B) horizontal support pipe.
Attach the straps and buckles around the frame (1 and 2). Note that these attach below the nearest horizontal support piece of the frame.
Attach the pack bag's bottom attachment straps (A) around the bottom corners of the frame (1 and 2).
We recommend loosening the turnbuckles if the pack is not used for extended periods of time.