1980 50 hp merc - impeller

[fastwin15]

hi y'all
before i replace the impeller on my 1980 50 hp thunderbolt, any tips? specifically, anyone know which gaskets in the area i should replace or will have to? also, is there any secret to disconnecting the driveshaft? i know in my older model outboards there's a cover plate for just such a thing but isn't one here.
thanks!

 

[racerone]

There is no need to disconnect the shift rod.----------Everything is splined !