Hello, it's not a terribly difficult job to do depending on the tools you have on hand, might have to add a tool or two to your collection. As for the task, of course you'll have to remove the wheel and support that the machine on that side with stands or blocks. Once you get the wheel off you'll see the wheel hub. That hub is a "tapered shaft connection", meaning it won't just fall off, it will be tight. Next pop loose the large hex head bolt in the center of the hub, this bolt is what pulls the hub tight to the tapered axle. Don't remove the bolt, just loosen and leave maybe a 1/8" gap between the bolt washer and the hub.
Now, you need two short bottle jacks, fit them on opposite sides of the hub, like one toward the front of the machine and one toward the rear, fit them to where the base of the jack is against the machine frame and the piston of the jack pushes against the back side of the hub. Pump up the two jacks to put some pushing pressure like you're trying to push the hub off of the axle shaft. These two jacks will not push the hub off, you're just trying to put some pushing pressure on the hub. Once you get this pressure, take a big sledge and whack the head of the big hex bolt that you loosened up, knock the dog snot out of it. In most cases this will pop the hub loose from the shaft. Now remove the bolt and hub.
Once you get the hub off and expose the seal, I typically drill small holes in the metal casing of the seal and use a small slide hammer with a sheet metal screw adapter, screw the sheet metal screw into the hole and use the slide hammer to pull the seal. It might take drilling several holes around the seal and pulling, but they typically pop out without much fuss. Clean everything good, drive in a new seal and button everything up in reverse order.