Summarize the following:
Each rail slides into slots on the post and is held in place with screws. Turn the screws counterclockwise to remove them. Pull both the top and bottom rails away from the post. If you have trouble installing a post, removing the rails and fence panels completely can give you more space. Remove the old post as well as any fragments that may be in the ground. If your post was held in place with concrete, you will need to dig up the concrete to remove it. To remove the concrete, dig out the dirt around it. You can refill the hole later. To figure out where to place the new post, measure the distance between 2 existing posts. The new post should be placed an equal distance from the last post. Mark the location with paint, tape, or another indicator. The post needs to be even and straight or else the rails and panels will not fit correctly. Dig out the spot you marked earlier. Make the hole about 8in (20cm) in diameter. You can use a tape measure to ensure the hole is the size you need. You will need about 120lb (54kg) of premixed concrete for 1 post. Place the post in the hole. While someone holds the post in position, fill the the hole with concrete. Pour the concrete until it is about 4in (10cm) below the ground's surface. The other person should hold the post straight. If it doesn't look right, adjust it quickly before the concrete solidifies. Fit the fence rails into the holes on the new post, then begin sliding the panels onto the rails. Screw the rails to the inside of the post. Then, attach the panels, screwing them in place if they also use screws.
Unscrew the connecting rails. Dig out the damaged post. Measure where the new post will be placed. Dig a hole 3ft (0.91m) deep in the ground. Seal the pole in place with concrete. Reinstall the fence rails and panels.