URGENT! Which screws do I undo to remove a push-out side hinged window?

Furniture is being delivered the day after tomorrow and the only way to get it into the house is by removing the window.
I need to unscrew the window from the hinge, but, would it be best to remove the hinge screws from the frame, or, from the window itself, or doesn't it matter?
The sealed double glazed window is approx. 45" x 50" has a hinge on each side with handle in centre at the bottom.
The windows were fitted by Zenith about 6/7 years ago.
Your advise would be greatly appreciated.