1964 18hp Evinrude how to seperate the engine from the base plate and leg?

I've replaced the coils,renewed the impeller and got the head off,but I'm unsure and a bit cautious of seperating the engine from the base plate/dish and leg.
Is it a mammoth task,or quite straightforward?
The reason I ask is because the screws in the bottom of the water jacket are not accessable and I need to get the water jackets off to replace the gaskets.
I have toyed with the idea of drilling the base dish/housing to gain access,and then using rubber grommets to seal the holes when the job is done.
Any advice will be gratefully received.
''V''

https://www.youtube.com/watch?v=O9mgepS1770 this may help.

newyota said:

https://www.youtube.com/watch?v=O9mgepS1770 this may help.

Click to expand...

Great find,thanks newyota,
not as difficult as I imagined,. I have a stand similar to the one in the vid.
Be an opportunity to do a full job on the motor.
Many thanks
''V''