Those are put on with red loctite so most smaller air compressors will not pull them off very easily. You are better off with a electric impact. Dewalt makes one that will pull it off in mere seconds. The first time I did mine with and air compressor the old fashioned way. It was gig, gig, gig, gig, gig, for like twenty minute before if loosened up.
The second time, 10 years later, it came off in about 2 seconds with the electric impact.
And as a tip, when you reinstall your clutch pack do NOT over torque. Simply set those bolts with blue loctite and tighten them until you feel them bottom out. A 1/4 turn too far and the bolts will snap right off. Don't ask me how I know that one...