Dig around the rotten post and cut it just above the rotten point with a reciprocating saw, so as to be able to pull it out of the ground. Then place a new second post in the hole, bolting the posts together. Making sure they are plumb, and then pour a new concrete footing to hold the second shorter post.
However it happens, once a fence post is broken, replacing it can be significant job, often involving expensive or specialized equipment. However, here's an .
How to Replace a Broken Fence Post. Depending on the type of post and how it was set in the ground, replacing a fence post can be a manageable job. Taking .
How to Replace a Fence Post in Concrete. Replacing a fence post may seem like a daunting task, especially if concrete held the original post in place.
Adding new life to an old fence with This Old House landscape contractor Roger Cook.
Repairing a wooden fence post or replacing it if a repair can't be done.. Problem number 1 is the fact that the broken post has to be removed from between the .