crank seal help??

[devon]

i have a 1983 244 robins and i would like to change the sleeve gasket and the cranks seals on it (i caught it on fire the other day)i know the sleeve gasket is not an issue but i do not know much about the seals on this thing. first would be how to remove the clutch and starter belt drive.it has a bolt at the end of the crank on this side and i do not know if it is under a lot of pressure or not..... nor do i have even a begining idea for the drive.... the other side i saw was as simple as pulling the fan with the ususal tool (what you can make).... puller..... and the only other thing is should i replace the main gasket that holds the split case together or not seeing as how i toasted the cart after dumpping too much fuel in the carb and letting it drop on the red hot engine...