If you want to just replace the oil seal for now, and rebuild later you can take the knuckle off using the modified Camo method.

Camo Method.

Usually you can get the whole knuckle off by taking the top steering knuckle off and then rotate the whole knuckle away and down from the axle. While you got your knuckle, hub, and axle out, clean out the old grease, repack with new grease. Change inner seal. Bolt back together. Good to go.