Hi, You should begin by removing the deck from the tractor.Remove the belts and the mandrel guards from the deck.Block the blade with a strong piece of wood so it can't turn and remove the nut on the mandrel pulley. This is difficult to do without an impact driver. Don't hold the blade with your hand you might get cut. Use an impact driver to remove this nut and the blade bolt if possible. Turn the deck over and use the wood to block the blade and remove the bolt holding the blade to the mandrel shaft and remove the blade.You have to remove the jack shaft from the mandrel to drive the bearings out of the mandrel housing. Put the nut on the threads of the mandrel and drive the mandrel shaft out the bottom of the mandrel housing. You can drive the bearings out with a screwdriver. The lower bearing will usually come out of the housing when you drive the shaft out. I attached the link below. Hope this helps!