Oil in belt housing?

This afternoon I took my 2012 900xp for a quick rip. about after 5 min. i noticed my belt was slipping. I returned home and opened the belt housing and about an ounce of oil was in the bottom of the housing.
After removing the the clutches and the inside half of the housing and cleaning everything up, I put the clutches and the belt back on back on and started the engine and ran it for about 2-3 min. The clutches seemed to work proper.
I then removed the belt and clutches again and found oil seeping from around the crank shaft.
My question is, is it possible to replace the crank seal without splitting the engine?
I know in many cases it is possible to make a hole in the seal and pry the seal out then tap the new sealback in.:confused: