The first thing to do is take the whole kitnkaboodle out of the machine.
Loosen the set screw but don't take the screw out. It is tiny and you might lose it. It will release the assembly without coming all the way out.
Next you will see the wavy washer.
This is what you get next. The washer is quite tight and the stop washer is even tighter.
Tension release pin
If it doesn't work quite the way you like it, fiddle with it. Move the check spring tail one "notch" on the stud and see what happens.
And make sure that the check spring sits in the indentation in the front of the disc.
Put the tension release pin in next. It will really only go in one way. The head is the part that comes into contact with the tension release pin washer which goes on next
The Stop washer goes next. It is snug. Don't force it. It must go all the way to the threads. The little tab should line up at the top and should match one of the cogs on the screw.
Next comes the little washer and then the numbered dial.
When replacing the tension assembly on the machine you will need the ring that goes between the tension assembly and the machine. It has a serrated notch where a pin from the tension assembly fits
I marked the set screw scar so that I could re- align it. You can see that I have had the assembly out a couple of times during this process today. New set screw scars.