Forgot about your towbar. Even if you loosened all the bottom fixings is it not possible. Maybe someone will be able to advise you of some way to remove it without damaging these. As said I have removed the rear bumper off my last two 320s and it was the same story. Saying that though mine sits alright after refitting but be careful and you should be ok. I would rather not remove not but if its your only option then it has to be. Good luck.
E92 330D LCI
NSR 250 MC21, CBR 600RR 3