Only problem with getting a friend over to help is I literally have none in this area. I commute over 40 miles each way to work, and pretty much am the only one living in that area of the people I work with.
As far as doing it without a tool, I used to be able to do that. Can't anymore. Working alone in the garage I have to be extra careful not to do something to hurt or trap myself. Have a detached garage, and my wife would never hear me screaming for help.
That door hanger looks interesting. I might be able to do that. But I definitely need something to keep the doors on and movable. 2 car garage, one side taken up with our good vehicle. Can't leave it outside once it starts snowing.
Using old seatbelts could be a possibility. I think I have some laying around somewhere.