just thought i’d mention this if anyone has the same problem of broken exup bolts.
I’ve just recently had my exup bolts drilled out and the threads re tapped, which is nice.
The remains of the broken bolts in the housing were harder than a very hard thing and resisted several attempts to drill them until my guy got some drill bits from a locksmith, these worked really well.
So, if you have the problem, don’t waste your money at machine mart or other such places selling titanium or cobalt bits, get down to you local locksmith and get the bits from them.