To replace you need to remove the fireclay bricks first then it will be a lot easier. I'm not sure if it works without it. I used a rubber mallet to knock the back edge out of the flange. I then used a couple of screwdrivers to bend the back edge towards you so it falls all the way down. It took a few tries to figure it out, but once I did it all went well. The more deformed the septum is, the heavier it can be. I would check and replace the baffle every year until it is too deformed. I vacuumed the rear flange so the new one was right up.