Hold the wrought-iron fence panel up to the block post, and line it up at the desired height. Have someone assist you.
Measure the distance between the bottom of the fence panel and the ground -- to ensure it's even in height to the rest of the fence and that it's level.
Mark where you want the screws to go into the fence post, using a pencil or piece of tape. The marks need to line up with the brackets on the fence panel. Mark for both the top and bottom brackets.
Drill pilot holes into the fence post using a drill bit that's slightly smaller than the screws you're using. Make pilot holes for all the brackets on the panel.
Align the fence panel's bracket up with the pilot holes, and screw the panel in position using long wood screws. Repeat for all the brackets on the fence panel.