After self cleaning cycle, we opened the top oven door and the inner pane of glass cracked. Do you know if the glass itself can be replaced by me (fairly handy) or do we need to call out for a repair visit? If so, where might we order the glass and do you have the part number? Also, I've seen a few of these posted...although the oven is 4 years old, is KitchenAid covering this under warranty/recall? Thanks...I appreciate any help you have!