Sorry, I'm a little late finding your thread but here goes. You will need a common paint stirring stick and help from a friend. Break the stirring stick into four pieces about two inches long. Install the rods into the latches (right angle end inboard, long rod to the left) then mount and torque the latches. Grip one of the rod ends through the center opening in the tailgate with a pair of vice-grip plires and pull inboard while your friend places two of the wood pieces (shims) in front of the latch pin to hold it inboard. Repeat for the other side.
Assemble the release mechanism before installation. The flat bar, with the two holes in the ends, goes onto the carriage bolt, then the waffer washer, and then the smaller but thicker nylon washer. I have seen many assemblies that the waffer washer was missing. You must have this part. If missing, hit the hardware store. Insert this assembly into the hole in the top of the bucket, then the larger but thinner nylon washer followed by the release handle and the retaining nut. I advise replacement of the stock nut with a SS ny-lock. Note that with the square carrage bolt there are four possibilities as to orientation of the flat bar and the release handle. The correct orientation is when the release handle is completely stowed in the bucket and the flat bar is perpendicular (front to rear). Torque the ny-lock nut until the assembly is very tight but still manageable when pulling out on the handle. Check that the waffer washer is compressed (not totally) and applying pressure between the carriage bolt head and the flat bar. If there is any slack, a flat washer may have to be added between the nylon washer and the waffer washer. If so, use a SS washer as they are thinner. If there is any slack, the flat bar could jump on the carriage bolt head and throw off the proper orientation.
Hold this complete assembly in place while installing the right release rod down through the forward hole in the flat bar (easy job), then a small washer and keeper on the end of the rod. Don't worry about the gasket, it goes on later. Install the left release rod up through the rear hole in the flat bar (difficult job). The problem is that there is not enough room between the top of the bucket and the bottom of the flat bar for the right angle of the release rod to fit. While your helper holds the assembly, take a stout pair of neddle nose pliers and bend the tip of the bar forward and work it up into the hole. Be patient and work together, it will go, then a small washer and keeper on the end of the rod. Don't worry about bending the release rod, it is made of high tensle steel and will spring back into place.
Now install the gasket. Note that it is the same on both ends but thinner on one length. The thinner length goes to the top. Gently pull it over the bucket and into place.
Install the connected assembly with gasket into the tailgate then the two bolts on the inboard side of the tailgate followed by the four screws on the outboard, then torque all.
Pull out on the release handle and have your helper remove the wood shims from each end. Exercise the release several times assuring that the release pins retract and that the release handle springs all the way back into the stowed position. If so, close and open the tailgate. Your good to go.