I am going to have to replace my side fence, which is set on top of a double brick wall approx 4 feet high. The 8-foot posts are sunk approx 2 feet down between the inner and outer walls. The posts are rotten and rather than dig them out, I am considering cutting them down to just below the top of the wall and then capping them with headers. I would then site the new posts about 1 foot to side of the original posts. Fixing the new posts seems relatively straightforward but I would welcome any advice you can provide. Many thanks.