Yeah I can visualize you with your legs flapping in the breeze out of the window.

I figured it wouldn't be easy. Even harder with a '51 or later truck with wing windows. That winch would have been the way to go for sure. Takes a little time to set up though.
If I ever need to pull a tranny with the cab on, I'm planning on using my engine hoist. Or maybe borrow a buddy's tranny jack.