Tommy, guess you need an army of volunteers to help you with it. I have the same problem getting my roof rack on and off-its 6-7ft. Im 5'10, but its the weight-weighs a flippin' ton!
I got pallets and laid them on my side of the truck so i got the extra height (the chap who was helping me was tall enough to reach ) and after it was unbolted, we lifted it and took it off over the back door-we yet to face the challenge of putting it back on when her ladyship returns from Larbert, but it'll no doubt be the same way it came off.
I would suggest you put some covers over the roof and back door to protect the bodywork a bit as well.