http://www.wotnow.ca/Images/LeafHarness1.gif
The top strap of the shoulder harness attaches to the top bar of the adjuster. The lower strap goes in front of the lower bar (under the adjuster clip), around the center bar, then under the adjuster clip. Both shoulder harness straps have an "L" clip at the end. These "L" clips are "left" and "right", so that they come together cleanly as they thread over the tang of the link, before the link is inserted into the latch. The anti-submarine strap threads onto the link, too.
HTH
Phil