On a 2011 Sportsman 500HO,I can't get the front prop shaft to slide so I can put seal in front diff.
What can I do?The previous owner only has a cotter pin holding shaft on front diff.:

 

Easier on the hands and knuckles if you have an air hammer with a dull bit. Remove this "cotter pin" get the correct clevis pin for later,impact the rear yoke toward the gear case. Prop shaft end will move rearward far enough for the shaft to come off the front diff shaft,move it over to the left to work on the diff plate. On assembly just impact the rear yoke forward enough to align the splines and holes,then impact it until the holes line up. Start the new clevis pin and impact it flush.

 

Try spraying the crap out of the splines once you get the cotter pin out and then a little light prying (carefully) should slide it back. Coat the splines with neverseez before re-assembly. I always replace the roll-pins with a bolt/nylock nut. They tend to work themselves out over time and can create havoc.