I doubt a ladder would be stable enough to be safe, especially when using a chain saw. A scaffold tower would be far better.
Otherwise I agree with this method
Tie a ladder to the tree (or climb it) and use a bow saw to take sections off, starting as high as you can.
It is easily cuttable (it appears to be fairly thin) without recourse to a chainsaw. A bow saw with a fresh blade is so much safer.
Use a short rope, tied just above and below the cut and the bits will not fall far. You can let them down on the rope once they are dangling safely.
No fuss and lots of control.Plus none of that damned noise that a chainsaw makes.
I've done that on several occasions and have all my limbs. You can't guarantee that with a chainsaw, especially if you aren't very skilled.
Or you could get a tree surgeon to do it for you.
Once you have solved your problem, I would certainly suggest that you leave the pieces of trunk to rot naturally. Once natures little recycling team get to work, the trunk will provide shelter and food for insects, fungi and, if your very lucky, perhaps orchids. It will take on a whole new beauty and interest.
Look at this piece of rotting trunk from what was a very substantial tree in Woburn Park: