A leaning fence post can make your fence look terrible. Improperly installed fence posts may lean when the ground freezes then thaws over the winter. As the ground freezes, it raises up due to the swelling of ice, and then it sinks once the ice melts and the water drains away. When you install concrete around the post, this is less likely to occur. Repairing a leaning fence post may require a partner to hold the post while you dig.
Dig the soil away from the side the fence post is leaning toward. Remove enough soil so that the fence post is free to move around.
Lift up the post so that it is straight without forcing the post. If you cannot get the post straight, dig soil away on the other side of the post.
Fill in soil on the leaning side of the post, underneath it. Fill in soil until the post stands straight up.