The installation of all 3 o-rings and the seal for the front end of my Kubota B2100HSD was very simple. The front axle has had a slow leak for years. I finally got at it and fixed it. Just raise the front of the tractor enough for the wheels to just clear the ground. Then remove the 4 main bolts. Nothing else has to be removed.
Thanks you Messicks for carrying old tractor parts