My cousin's 029 had the spark plug blow out and strip the plug threads completely out. We started taking it apart so as to install a new cylinder kit. The cylinder bolts were very TIGHT and we got three of the four out BUT the last one which is the deepest one into the plastic case had the torx head on the tool break off in the bolt head. WOW, never thought I would see that but it happened. We now are baffled as to how to remove this last cylinder bolt and we have tried drilling it BUT this thing appears to be made of concrete as we can't get a single drill bit to drill much into it. Anyone have any ideas as my cousin went and bought a cobalt drill bit yesterday and it merely spun on top of what little drilling we have got into the bold head. We do have the cylinder and plastic housing on a drill press but so far we can't make much of a dent into the bold head. Sure hate to tear up the plastic housing as then replacing it will make the repair cost more than the saw is worth. Looking for opinions on how best to proceed.