Apparently depends on both shaft and tube diameter. The shaft is 1". Not sure what the tube is.
Unfortunately, with all the work required to replace the PSS seal a haulout is reqired. You can begin some of the work while the boat is in the water and still being used. If you do the work yourself...... as soon as practical measure the hull tube and order the new shaft seal. You will want time to carefully read the instructions for installation. Mind-set is very important ......be prepared to spend some quality time in uncomfortable positions in your engine compartment! (Classical music is helpful for me.)
In preparation for the job put your choice of penetrating chemical on the coupler bolts where it connects to the transmission and get some onto the coupler to the shaft where the shaft key is located. Soak those areas over several days to a week or more. Drizzle some into the holes in the ss collar too. A thin chisel might eventually be needed to tap out the shaft key, but be gentle.
Another PITA: When the boat is hauled out check for wobble in any coutlass bearing you have on the shaft. While you are doing the PSS you might as well check/change the bearing as needed.
The prop shaft willl need to be moved aft in order to have room to work to remove the coupler from the shaft. Then the ss collar and the remainder of the dripless shaft seal (which has become a dripping shaft seal) can be slid forward and removed from the shaft. Remember, there are two set screws in EACH hole in the ss collar. They will probably be corroded too.
When those old parts are removed check the prop shaft for wear. Preparation proceedure is in the instructions for installation of the new PSS. Definately clean and smooth the shaft prior to putting any new parts in place. If it is worn or deformed it will need to be replaced. (Sorry to need to mention that!) But, that is a whole 'nuther project!
When the boat is back in the water you can check for proper compression of the ribbed boot by running the engine. I think the instructions mention that the seal will seat itself within the first half hour of operation. Slight adjustment to the bellows can be made in the water. (After you have shut off the engine!)
Best Wishes for a successful project.