E46 Coupe bumper got snagged

Hey all...

had a mishap this morning. while parking at the shops, the front part of the bumper got snagged onto the pavement a little. as soon as i heard the noise, i stopped and put into reverse slowly. i heard a shrieking, scraping noise and the front right part of the bumper got pulled away quite badly.

the bumper didnt come off completely, but its very clearly out of alignment now.
i was going to try and refit it this evening, but not sure how to do this, or if anything may have got damaged that might stop it from fitting correctly again.

any advice?

thanks!