the best way is to ask the craftsman who made doors if he will reduce the size for you and put a build up on the bottom,you will have to buy new glass units for all 3 doors,if not its new doors i'm afraid unless the head of frame is big enough to take some off then put a build up on bottom then you wont need to buy new glass.hope this helps and good luck with your prob
shaun www.sdwupvcrepair.co.uk, January 2009