I can't find a good guide for replacing this seal, but somewhere I read online that you might have to take the case apart to smash the seal out from behind?

Anyone have any experience with this? Also is it safe to use a breaker bar on the yoke nut with the case in 4 part-time to stop it from spinning?

 

You don't have to remove the front output seal by taking the TC apart, it is removed from the front by prying it out with a screwdrive or seal removal tool.

The FSM says to place the TC in 4 Low to remove the yoke nut.