Gather these parts first

Glue three struts onto the back of each billboard plate

Gather the base and the rail

Glue the assembled billiards onto each side of the rail and base as shown

Glue the hooks into the slots at the back of the rail and base plates as shown

Glue the slanted plates into the slots at the bottom of the billboard struts as shown.  Also glue in the support struts through the bottom of the base.  You may need to rotate them into place as they are a tight fit.