Pretty much as you said, but nut comes off first, then pinion yoke, then you can replace the seal.
Nut is well tight 250ftlbs+, I couldn't shift mine even with a 3/4 windy gun, used a long bar instead.
I made a 'thing' that bolts to the yoke and has a socket on it to hold the pinion steady, as without that the car will move as you try to get the nut off
Others may have found a better way....