Loosen all the main caps and pry down a little on the crankshaft a little so it gets some room between the crank and the upper rear seal, use a 1/4 inch drive extension to push the seal up on one side so you can grab and pull it out with a set of needle noose pliers.
Installing the new one is the hard part whiney wrench
Before you remove the upper half make sure the rope seal is leaking and not just the side seals, look hard at the engine side of the crankshaft flange to see if it has oil slung out onto the flex plate and not blown back onto the flex plate from the oil pan rails scope
If the side seals leak they usually won't leak onto the crankshaft flange like it leaks from under the main seal on the rear mains scope
Good luck thumbs

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)