Unscrew the prop cone and it comes right off! Gotta take out the central allen bolt first. Depending on age you'll either have a multi tab washer or a nylon washer behind the cone.
Did it very recently...just used an allen key to remove the centre bolt then put a bar though the hole in the cone, jammed the prop against a wooden chock and undid the cone. The prop came straight off. The allen key is an imperial size not a metric one ( well it is on my boat anyway...)...Good Luck, Iain