The rear stock mount bolt,once removed,allows access to the tension adjuster via an allen wrench. Clockwise to tighten. In most cases You will want just enough tension on the mechanism that it will remain in ready to fire position (forward) after being pushed forward and the muzzle is raised. (Shouldn't just slide back loosely)It should remain so until the rifle is given a light to medium bump on the butt stock with the heel of Your hand. It's a bit of trial and error type of procedure.
This is how I have my D54 T06 adjusted and its Incredibly accurate! Your 54 sounds like its way too tight. They are held in place by a spring loaded ball bearing type of detent that slides into a recessed section on the mechanism. Too tight is not good as it can create galling.
Sorry if it seems like I'm rambling,it's been a Long day! It's obvious how it all works once You inspect it.
Hope this helps!
Mike.