Hi EZFEED,
Sorry for the huge photo here but I thought the higher resolution will help
you see. Bill's description is great! Maybe with my photo and some more generic
terms you can see the mainsheet and almost how it rigs. This is the only photo I had handy.
Look at the mast, the up and down stick holding the sails. See the black tape I have in it
marking where I position the boom? The boom is the for and aft piece that holds the
bottom of the main sail. Follow the boom back
( barely visible ) and see at the
far end of the boom a set of blocks and lines!
The blocks and lines are all part of the main sheet. The main
sheet is used to controll how far you pull the boom in or how far you let it out.
Notice the bottom block has a cleat to hold the line! I see yours in you photos
is already attatched the the traveler which is that slide and ropes
on the back of your seats. The other end
of the main sheet clips to the end of the boom as in my photo.
The line goes up and down through the upper and lower pully
I believe 4 times giving you 4 to 1 purchase when pulling the
boom in! Study the photo and look at your stuff. You'll likely
have to untangle the lines but it is doable!
Hope this helps!
Scott