Cut and fit the winch post components as below. Predrill the winch plate to suit the hole dimensions of your winch and ensure that the winch post is not in the way of fitting the mounting bolts when the winch plate is welded on.
Only weld the brace plates to the drawbar along the edge of the drawbar section and not across the top face of the drawbar.
Align and fit the coupling plate (drill to suit your coupling hole dimensions) and weld on the shackle plates on both sides of the drawbar "A" frame.
Australian Trailer Builders -
Now is a good time to fit the safety chains to the trailer - the safety chains must be permanently attached to the trailer (welded) and the weld must extend around 50% of the circumference of the welded links and the adjoining links must have free movement.
Weld the safety chains as near as practicable to the coupling - they must be mounted one on either side of the centreline of the drawbar.