Measure 2 inches down from each fence post's top and make a mark on the fence post's inside edges. If the fence's manufacturer suggests a different measurement, use that measurement instead. This mark indicates the top bracket's location.
Hold up a vinyl fence panel the way it will be positioned on the fence. Measure from the top rail's top edge to the bottom rail's top edge. Transfer this measurement to the fence posts' inside edges and make a mark. This mark indicates the bottom bracket's position.
Line up a bracket's top edge with a fence post's top mark. Place a small level over the bracket and straighten the bracket as necessary. Insert a Phillips bit into a drill and drive the four provided screws through the bracket's four screw holes.
Line up another bracket's top edge to the fence post's bottom mark. Hold a level over the bracket and straighten the bracket. Drive four provided screws through the bottom bracket's screw holes.
Continue positioning brackets on each fence post at the marked locations.