I didn't but it really was straightforward. Hardest part was lifting the new box up and on, they weigh a ton. Only modification I had to make was to drill and tap two holes for the defender handbrake bracket but that was easy. All you have to do is chock wheels, remove front and rear props, remove handbrake drum assembly, remove handbrake bracket from the side of the box, remove handbrake backing plate, remove speedo cable, remove hi/low linkage and diff lock linkage from box. Then just drain the old box and its just a case of taking out 4 volts at the rear, two at top and two on the left side. At the front you have two threaded studs, just on the left when it fits snuggly against the gearbox, remove the nuts from these. After that with a bit of wiggling the box will come free but you need to support it as its heavy bit of kit. Could use an engine crane but I just rigged up a pulley to take the weight and lowered it down. You may need to transfer the threaded studs onto the new box but that's easy. Fitting new box is reverse of what you just did