I think I've figured it out. Unwind a length of line (I'm not sure how much it takes) and find the halfway point. fold the line at that point and hook the fold into a slot found at the middle tier of the spool. You now have two lines to wrap around the two empty cavities of the spool. Wrap both lines on at the same time. Leave ~15cm on each end to slot through the line holders (non-spring end). Follow the rest of manual instructions. Without pictures this is hard to describe, hope it helps!
GK, November 2009
