Sorry to hear that Tonie.
You can pick up a stainless steel engine bolt kit for about £12 on eBay, bleed nipples are a few quid each.
Assuming said numty hasn't done a similar trick with the banjo and brake mounting bolts you should be able to bleed the back brake by taking it off and angling it to get the bubbles to the inlet, then squeezing the pistons in to push the air up to the banjo at the top of the master cylinder where you can let it out... fiddly job, but it does work.