Christ I've just spent a day and a half on this. What a poxy job. Had to cut a slot in the flange of 3 out of 4 to get what was left of the stud out after drilling. Exhaust side holes cleaned up ok. No drilling or cutting required. Front breaks to do tomorrow. Then my son is taking this car up to Paris where he lives. Free's up some space for me at home. Don't panic I still have my other Z4 so won't be leaving anytime soon. Hope everyone had a great Christmas and all the best for the New Year.