Replacing Gearbox seals

I am planning to renew some seals in my 73 gearbox this weekend. I'm taking the gearbox out to do swinging arm/ cradle stuff. I bet your all jealous just thinking about it.

I think I'm right that they can all be done from the outside with cases/covers intact. I need to do the two o rings on the spindle bolt and quadrant spindles - looks easy enough(ha ha), but I'm a bit more concerned about the sleeve gear bearing seal - it can be done this way can it?

Any advice appreciated
Rob