I can tell you that we JUST pulled a gear from a 8594 and it was more than just a light press fit and it was very difficult. We destroyed the hex opening on the shaft tip getting it off, trying all the conventional methods. Your best chance would be to heat the gear and then use a gear puller, but be sure you put something over the shaft end to protect the
oil drive shaft insert, which is very soft. We wound up buying a new shaft, and the machine shop that reinstalled the new gear complained that it was a very tight fit going back on.