M-25 Alternator Mount Conversion Kit "B/M 256891"

[scrimshawsc34]

Hey all..  is there a step by step guide on doing this replacement?

[KWKloeber]

Yes

See Rod Collins' (aka Mainesail) article on his website.
MarineHowTo.com

Note that, and Rod explains this, but  if the exhaust manifold studs are not long enough to accommodate the bracket, then the project expands exponentially.