I used a big pipewrench to hold the flange(biggest one you can find). Then I used a big breaker bar to loosen the nut. Have someone hold the pipewrench for you while you put pressure on the nut. Impact wrench won't work since it will vibrate the pipewrench off. You have to position the wrench so it grabs the flange and won't slip.(position it on the very end where the bolt holes are; use both opposite ends of the flange between the pipewrench) Pipewrench sells for 20 bucks or so at homedepot. I think it is a 36" wrench. ========= (0) = (flange) (0 (nut) 0) = (0) = ========= = = = = =