"Use 2 carriage bolts of the right size to hold the first weight on. Then in the other 2 holes put 2 longer carriage bolts through the other 2 holes and tighten them down leaving enough treads sticking out to put the other weight on." That is basically what the manual says to do and you are on the right track. Not knowing what wheels you have on your tractor you might need longer bolts for the second 2 weights. Roger