Well, I feel foolish (again). I tried all of the instructions that others have posted (to which Douglas pointed me) to no avail. I just don't get it.
My "L" brackets are attached to parts which are welded to the B pillar posts, so if I push the B posts, the "L" brackets are forced down. There is no way to prise the "L" brackets up whilst pushing them down.
It appears that two people can simply push against the B pillars until the "L" brackets swivel down, which I think is what the net effect is supposed to be. But, in doing that, something may become bent or otherwise damaged since the result is the application of significant force on the bottom bow against the rear of the cavity.
Any additional advice is greatly appreciated here. Like my soft top, I'm stuck!
Joe2