if it's a pto seal only.. it's about 20$ for a new seal and gasket.

make sure it is not a bad bearing... with machine off.. grab shaft and see if there is in / out movement or side play. if none.. it's a realitively easy fix.. just make sure pto engagement is 'in gear' before you slide her out... and tip nose down to prevent loosing oil.

it's about a 6 m job to pull the 4 bolts, slip the shaft out, pop out split rings.. drop bearing carier off shaft/bearing.. drive out seal... seat new seal.. lube.. clean carrier, reset shadt and split rings.. clean gasket surface, add gasket, stab hole and slide home. put in 4 bolts.