Alan, if same as W.Discus Ketch (33), remove prop, undo grub screws on side of stern tube, insert something stiff & rigid that will grip c/bng and pull!, reverse procedure to put new one back. If it is really stuck, you may be in for prop shaft removal.....but normally they come out with a bit of a struggle. HTH.. Tony W
Got mine done a few years back. Remove prop and undo the two nuts holding the housing. If you have lived a good life, they will come off no bother. Mine did not and required a very small thin bloke with extremely long arms to hold a socket on a long extension bar on the bolt heads inside. Under the fuel tank and down the tunnel! Once you have the nuts off, the housing comes off easily enough, the hard bit is breaking the grip of whatever gunk was used to seal it to the hull.
With the housing off, the usual brutal methods are used to remove the old cutlass. I think there are two grub-screws. The new bearing is then pressed in. Re-fitting is a reversal of the above, again calling on Quasimodo to attend to the inside bolt heads. It cost me £120 in labour (C$300) for the whole job. Good luck.