I have one they are a heavy sucker, if you still cant work out where the knobs are from load up a photo of them or describe them and I ll take some photos, there are lots of knobs on this beast.
The rear standard slides all the way forwards to the front standard and there are a couple of pins that slide into the bottom of the front standard and you lock them in with a couple of small screws that lock it in, then you unscrew the large knob in the middle of the slide and that folds up against the back of the rear standard.
Again I can take some photos if you need.