Once the block is removed
The method I prefer is to take a long, skinny bladed shovel and dig out the dirt just to the side of the concrete exposing the side of the concrete block. Just remember to pile the dirt close to the hole as the dirt you remove will be used to re-pack the hole once the post and concrete block is removed from the ground. From the edge of the concrete, dig out about six (6") to eight (8") inches and down twenty-four (24") inches. This allows for a pocket as wide as the concrete block. If a piece or stump from the existing post is still in place, you can use it and start moving the concrete block back and forth using the new pocket space you just created. Once it is loose, you should be able to use your shovel or pry bar as a lever and lift the concrete block from the hole. Be careful and make sure you lift with your legs as the concrete block can weigh as much as eighty (80) pounds. If the existing post or post stump is no longer attached to the concrete, you should be abl...