Speedometer Gears Ground

I have a 95 Tracker and the gears for the speedo in the transfer case are ground to bits. Don't know how it happened but it did. The one on the cable end is easy enough to change but I'm not sure how to change the one in the transfer case. If anyone has done this or has any ideas post em up. I'm lost on this one and I don't want to have to take out the whole t-case.