how to replace tail shaft seal?

yes you can pull out the seal with a short , strong hook, or a slide hammer sort of tool. Now here is where the , 'it depends' comes in. Some seals also have a metal outer lip that a chisel or flat screwdriver can be tapped against. GO all the way around tapping and you can remove seal that way. Some dont have enough lip to get an edge on.
Installing needs to be done more careful. Using a round pipe nipple or similar like a socket to use as a pounding drift is the key. I needs to go in straight.
As your dad always told you , lube before insertion.

Always works best if it below freezing out to do the job. That way the seal contracts and goes in easier. So 9 pm is ideal.

red