Just did the this seal change on my 2012 txt 280 pro after draining emulsified oil out of engine. This video was excellent viewing beforehand. Did it with pump still attached to coolant pipes - bit of a fiddle but avoids breaking the original factory pipe clips.
I actually have a short video that shows how easy it is to release and reuse those hose clamps - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-6sAerXIhHMk.html
Superb. . Exactly what i have to fix. . Im sure water is getting into my gearbox oil on my 03 txt. . It looks milky through the sight window, and the gears have gone very clunky. .