HMMMM not sure about that Len, however some penetrating oil and then trying turning the other way might loosen it all up.
I assume you cannot remove the prop tube? They often respond well to a big hammer!
Roy

It may be possible that the lock nut may a left hand thread so you can try to turn it as if you were going to tighten it to see if that helps.

I would try some heat from a soldering iron that can usually unglue loctite.

Roy

Hi garyp
If you have a threaded coupling at the motor end also with a lock nut, you should be able to hold this in some pliers and use a thin spanner or pliers to undo the lock nut and prop. Try tightening the nut a little first to break the seal. You should then be able to grip the prop in some thick cloth and take it off.
That is the easy solution.
If this doesn't work then, remove the shaft from the boat, you will have to disconnect the motor fittings and possibly also remove the rudder.
Once the shaft is out you can use a vise with paper wrapped round the shaft to hold it and then remove the locknut and prop as above.
Hopefully the first method will work.
If you are not intending to use the prop again you could use more destructive holding methods.
Good luck and please let us know the end result
dave976