caterpillar 336 el starter removal (flood damage)

I lost a 2014 336 to a pond and it has water damage. I am trying to get it back running again. Because it was in mud/water I think the starter has failed. It is also winter 20 degrees here in Michigan. Between corrosion and freezing temps. We drained all the water and got machine running initially but it has now sat for a week in the winter and will not roll over. I ordered new starter from cat and cannot see an easy way to get the top bolt off the starter. Has anyone removed the starter from a 336? thanks