Whatever it is, the ceiling replacement is at first its removing and then in reverse order - setting. We will describe only the first part. Immediately tell, there is an opinion that you have to cut the rear window. It is not necessary. It is possible to push the ceiling through the back door, perhaps bending a little, but it will not be noticeable. Fold seats, pull out head restraints and let's go.
In order to remove the ceiling, at first you have to unscrew the visors, remove backlight lamp and lateral racks (paneling trim). There is nothing complicated. A lamp is just pulled down, the same as lateral racks (it can be not removed only between doors in the middle of a car). Visors are unscrewed with a screwdriver ... as handles. And then we move it back in a centimeter or two and go down. Remove, as has been already mentioned, through the back door.
The ceiling pasting independently is not very good option - it may not work.