This is how I do it if I need to mount it by myself on my land cruiser. I have a pictures of it somewhere, but it's pretty self explanatory. Snatch block, small harbor freight 2000lb winch anchored the reciever hitch of another car, and a big tree. I'm lucky enough to have a tree in the backyard that's at the right height and already has a few ropes tied to the limb for a swing. Otherwise you'd have to climb up and tie an attachment point everytime, and it has to be pretty high. At least a few feet higher than the top of the mounted tent when you take into account space for the pulley and rigging slack.
I modified my tent with mounting channels that extend past the tent and attach directly to gutter mounts, so the whole thing comes off in one piece. So taking it off is easy, but putting it on requires some maneuvering of the car to get the tent close enough to swing into place. If I use the stock mounting channels it's easy enough to rest it on the cross bars and slide in place. I've also done it without the hoist system using a couple of ladders and 4x4's to make a giant ramp, and even an engine lift, but the winch system is probably the safest and easiest.
When I mount it on shorter cars like my minivan or subaru, it's quicker for me to rest some moving blankets on the rear hatch, stand the tent up vertically on the bumper, then lift and slide it into place. You still gotta wrestle with it a bit, but as long as you don't have the XL versions it's doable.
Edit:Found a pic of the setup