Locate a spot on the lower, center section of the snow plow frame, and hold the mounting plate against it. Mark the mounting holes of the plate on the frame, with a crayon.
Drill out the marked holes with a drill and metal boring bit.
Hold the mounting plate against the frame, and insert the bolts through the plate and the drilled holes.
Screw the nuts onto the back of the bolts. Hold the bolt in place with an open-end wrench, and then tighten the nuts with the socket set.
Align the hitch arm with the mounting plate, and slide the arm downward on the back of the plate to seat it into place. Insert the carriage bolt, and tighten it with the open-end wrench.
Slip the hitch ball post, on the bottom of the ball, through the hitch arm mounting hole. Screw the bottom retaining bolt onto the threaded bottom of the hitch ball post by hand, until it cannot be turned any more. Tighten with the pipe wrench.