My advice on the big trunk is to make your first split with a chain saw. Once you have it in halve, splitting the rest is much easier.
My friend George and I hauled a huge osage tree out of the woods that George wanted, close to 30" in diameter.
I wanted to make the first split with a chain saw, George wanted to split it the old fashion way.
The temperature was over 100 every day and it took George a month to reduce this pile to staves.
The bad part was after all this work the osage was substandard, brittle and didn't make good bows. Most of it went to George's burn pile.