MCHITCH
Heritage Softail Hitch Installation Instructions

Install left and right side plates as shown below, using the stock bolts.  Do not tighten yet!

Install bottom plate on top of the side plates. You should be able to move the side plates to get the base plate on top of them.
Insert 4 carriage bolts (included) through the side plates and base plate. Install 4 nuts (included) onto the carriage bolts as shown below.

Now tighten the side plate bolts and the bottom plate bolts.
Install ball (not included).