Will it fit through with just the door off or do you need the frame taking out as well ?
If it's just the door then don't take off the hinges themselves, you'll never get them back on straight again:
Open the door and have a look for a small hole in each of the hinges, these "should" have a small grub screw in to keep the hinge pins in place, if they're there they just need to be screwed out, if they're not it's because a lot of fitters don't bother putting them in.
Using a piece of metal slightly thinner than the pin (I use a long thin screwdriver) tap the pins out by knocking them up (depending on the type of door you have you should be able to do this with the door closed, push the handle up before you do as this will lock the door into the frame and shold stop it falling on you
When you have taken them out support the door (easier with two), push the handle down and then pull the door our of the frame. You will notice that the hinges have small pieces of plastic between the door section and the fixed part of the hinge, they are called (or we used to them) "top hats" because of their shape, they stop the metal parts from rubbing together as you open/close the door, so try not to lose them as often they drop out, just push back in.
Put the door safe and to refit is just the reverse, you shouldn't need to adjust the door as the pins should put it back in exactly the same place.
It's not complicated at all and can easily be done (remove/refit) in under 10mins (under 5 if you've done it before), but these doors (especially if all glass) can be heavier than you think so ideally have two people.