I have the wsm for the b7400 and b7500's but it doesn't cover removal of complete diff housing. I need to remove and replace the complete ( rectangular aluminum) housing that is bolted behind the transmission case. In the parts book, it is labeled as C425-differential gear case ,: 6c040-1117-4. A rock took a chunk out of the aluminum, leaving a hole. Most of my fluid spilled out. I bought the new case and whatever I think I might need to replace while in there, seals, bearings. I'm just trying to figure out how to do it. Is there a different manual that goes through the process step by step? Any advice. I have to do this outside and I am feeling like my window of opportunity will be closing soon. Thanks, Andy