does anyone know how to replace it?
I did mine and followed this write-up, it only took me about 4 hours, its not too difficult. get all the tools together first and be sure you have at least 18" of extension to get to the bolts. and be sure you have the 2 crush washers.
It also helps to have someone to help "feed" it out once you get it unbolted, and then to feed the new one in.