Now that you have the turnbuckle disassembled you may begin the installation.
To install, take the cable end from the turnbuckle and, starting at the last vertical of the cable run, thread the cable through all of the vertical posts to the other end.
Attach the jaw to the vertical or pass the threaded termination stud through the vertical (depending on the type of termination hardware).
Now take the turnbuckle body in hand and holding it between the cable end and the termination stud or jaw begin threading both ends into the body simultaneously (end fittings must be evenly installed). Continue to turn until tension is felt.
Make sure cable is through all verticals properly and is not caught or pinched.