Don't know your exact engine room layout, but generally:
- disconnect the propshaft from transmission. slide the shaft back if you can, depends on type of shaft seal
you have, are you in the water
? clean and check the shaft for burrs before sliding it into a stuffing box. Dripless seal may not allow you to move the shaft back without disasembly. Depending on the length of the shaft and bearing arangement you might be able to lift
it up or down so that the transmission can be pulled back. Another option in some cases is to disconnect the engine mounts and slide the engine forward. Or pull the engine.
- disconnect the transmission: cooler, control cable, mounting bolts.
- pull the transmission back out of the damper plate and place out of the way.
- you should now have access to the damper plate. remove it, probably has some broken or worn springs, replace it or have it rebuilt.