I did leave the upper unit attached to the trumpet and lifted the whole assembly together. But if you can get a lifting line around the trumpet itself that may work just fine. I recall having to put a tremendous amount of tension on the lifting line with my winches and then tap with a hand sledge, kick it a bit with my foot and rotate it back and forth before it finally popped loose.
Did you find the lifting tang on the overhead above the c drive? I didn't find that until after I had removed the unit and I think it would have made it much easier by giving a straight up pull.
On mine, the trumpet came out of the boot, but I may have left the lower clamps in place. Regardless, the boot should not give much resistance to the removal. It's where the trumpet mates into the hull with a couple of "O" rings that seemed to be the sticky bit.
By the way, I had removed the bolt holding the lower unit to the keel and wiggled the lower unit around to help release the drive shaft spline.
Good luck with it - hope this helps a bit,