How do you change crankshaft seal riding mower?

First things first. Make sure the engine is cool. Remove the hot battery terminal. Put a large drain pan under the mower and completely evacuate the oil. Replace the plug. I Use auto ramps and a small floor jack to raise and lower the deck. Pull the holding pin or pins from the front of the deck once you have the jack in place and let it down slowly Remove the keepers and the deck belt from the pully shaft, then let it down the rest of the way. The drive belt will sneak past the keepers when you get the pulley shaft loose. Once you remove the pully shaft that is bolted underneath the crank, (I use a pipe wrench to hold it while loosening the pully shaft bolt) you will see a rubber coated metallic seal. Using a small thin bladed screw driver, work at the seal carefully until it drops down. If you drained the oil completely you won't get a bath. Use a towel or clean rag and wipe inside the trough thoroughly. Place the new seal over the crank and gently push it into place. If you have a small rubber mallet, you can tap it all the way around until it is flush. Take the mower off of the ramps and fill your mower with oil (I use 30 weight in summer ) a little at a time making sure you don't overfill it. Be sure none of the belts are near the crank. Replace the Hot terminal and start your mower. After 5 minutes or so, grab a flashlight. turn off the mower. remove the hot terminal again, and after putting the front tires back on the ramps, check it for leaks. A little seepage may be present. As long as it isn't profuse, don't worry. I would leave it sit for 20 minutes to be sure. If no leaks, replace the pully shaft, the belts, deck holding pin , then the keepers. Set it down. Connect the terminal and you're ready to roll.