Check out the Downloadable Barnett's manual chapters in this section (I think - They're on the forums somewhere). Look at the table of contents that was posted and read the section about rear der. adjustment. It will walk you through everything, and even includes a trouble-shooting section. I own the set of books and it worked great for me the first few times - I am now able to adjust it without any help from the books/references.

-Moab