More often than not, when these bolts break they can be backed out using a sharp transmission pick. The bolt holes are very short and the bolts insert just about all the way and bottom out so they don't usually stretch or damage the threads. A small left handed drill bit applied as close to center of the bolt can also run the bolt out. If you are replacing any of the vacuum pump bolts with anything other than the correct Ford replacement parts be very sure to pay attention to the length of the bolts. You literally have about 1-2 mm of extra depth using the stock bolts. As I mentioned in another post, if you are replacing the primary water pump be careful not to mix up the vacuum pump and water pump bolts. They are not the same length and if you place water pump bolts in the vacuum pump they will bottom out before they clamp on the pump... and this is typically when you have a broken bolt situation. BTDT.