Also its a 2 man job. If you try and hold the new box in place whilst getting the bolts in and started it will get right up your nose... All my pipes came off ok with a normal spanner, maybe soak em for days in wd40 first? If you are getting a second hand box (or new for that matter) get one with a drop arm and a decent ball joint. Them drop arms can be a real swine to get off!