I think you're talking about the stuffing box. For that you
don't need to remove the engine,however, you do need to
pull the shaft and sleeve. Though it's a little bit more
complicated than removing the shaft from a fixed prop. I'm
pulling the shaft this weekend- I guess for the same
reason- there is leakage and I'm putting in a replacement
stuffing box. Before I had a fixed blade prop, I had to
pull the shaft+sleeve , and like I said, it's a little
harder to do. You need to loosen the bolts holding the
shaft (and be carefull not to loose the key when you pull);
and you also need to loosen the nut holding the sleeve (and
be carefull not to loose the 2 rings holding the sleeve).
Put a towel into the bilge- you'll find the peaces easier
that fall down...

Wilhelm, V-257