If y'all wanna play automotive twister and do it the hard way, have at it.
I did it the hard way twice (by myself) before deciding to get smart about it, so yea, I know it can be done.
You can't impress a car by doing this kind of stuff by yourself, so why bother?
When you get a little older, you'll understand there's a limit that the body can take at weird angles, and blowing up your back doing something "heroic" is just silly...
In addition, your next thread could very well be "I put in my sunroof and it doesn't slide nicely"
Well, duh, you bent the roof mounts or the sunroof frame, and you get to do it again.
Supporting it with a ratcheting tie down strap takes less than two minutes.
It makes the job so easy it's like cheating. Everything lines right up, you can start all the hardware, tweek it into it's final position, tighten shit up and be done.
Ask for help from a friend, or be smart about it, that's my last word on the subject.