OK, I got helped on a different bimmer forum, basically to remove headlight assembly on E70 or E71:
1) loosen screws on bumper
2) undo the blind-rivet along the wheel plastic arc there are 8 of them
3) remove wheel
4) remove splash guards they are rivet, 8mm screws and one torx screw


the blind rivets need to be replaced, not reusable items.