There's a metal clip under the edge of the stainless steel washer thingy that's on the driveshaft just in front of the carbon ring... you have to pull the stainless steel washer thingy back towards the stern of the hull about 1/4" to expose the clip on the shaft, then push the clip off with a flat tip screwdriver or something similar... it ain't fun nor easy! I'm not sure how you got the shaft free from the motor without having this clip off already, or did you take the bellows that holds the carbon ring loose (which should not have been necessary and doesn't help to remove the shaft from the hull)?
Anyways once the clip is off you slide the driveshaft out the back leaving the stainless steel washer and carbon ring inside the hull (the carbon ring should be left attached inside the bellows actually).
A Speedster isn't a PWC is it? This is a PWC forum not a boat forum there are some differences.
Good luck.
- Michael