Caravan window repairs

Had a bright idea this morning, will remove the fly screens off the caravan windows and give them a clean ready for the soon to start trip to North Queensland. Well to remove the screens you have to fully open the windows and these particular windows have never been fully opened before. On winding them back down two jammed at the top section in the hinge and has broken a piece of the corner of two of them. I will need to remove the top hinge section and the question is. Will I need to remove the whole window frame from the van or can the glass and frame be removed without going to that extreme? I had to remove the boot lid a few years back to make a similar repair to the hinge and had to take the whole frame out to remove the lid,I suspect this may also be the case. Maybe someone has also had this happen and can give me a few pointers in the right direction, any help appreciated.