Ayuh,...... Welcome Aboard,...... Hopefully the propshaft was greased when it was last put on,......
The castellated splined washer, aft of the prop, ahead of the tin lock, 'n nut, Should just slide right off,......
If not, try a few light taps with a hammer,.....
If it continues to argue, 'n the prop is in the same condition,.....
Ya might just have to decide what gets destroyed, to get the prop, from the drive,....
'n it's never pretty,....
Grease is the key,......
A well greased prop, 'n shaft, don't corrode, 'n seize,.....