hi there
The way I myself overcame this problem on my model of the Seaforth Clansman; was I manufactured 2 brass plates which the bottom of the rudder post located in. This was then bolted to the bottom of the Korts nozzle. So, to remove the rudders & gain access to the propellers, all one has to do is remove the 2 securing bolts on the plate and do the rudder linkage inside the hull and the rudders slide out. What I think FLJ is referring to when he mentions the Collet - this is mounted on the propeller shaft on the inside of the hull - between the end of the prop shaft and the coupling, preventing movement back and forwards of the prop shaft.
Now if you undo the Collet and coupling, and slide the prop shaft back into the hull, whilst unscrewing the prop shaft from the propeller - this should allow a clearance for the propeller to be removed from the back end of the Korts nozzle.
Ive included a little sketch to try and explain the method I used. Hope this is helpful to you.
Aye
john e
bluebird