STEP 1 : Module + Case
To assemble the Module with the Case, slide the Module from the top into the Case without forcing (figure A). Alternatively, you can also slide the Case from the back into the Module (figure B).
STEP 2 : Module + Case + Tension Ring
To finish the assembly, take the Tension Ring and screw it clockwise into the thread at the back without forcing. Tighten it until you feel a resistance and the Module holds firmly into the Case.
STEP 3 : Strap
To assemble the Strap, slide one of the pin of the Strap into the hole of the Case and lift up the Strap into position while using your thumb or index to push on the quick release pin. Once clipped, gently pull on the strap to ensure it is securely locked in its place.