Rule of thumb is if you can feel them with your finger nail, they aint coming out. Generally your only chance to get them out past that is wet sanding it, and then buffing the wet sanding scuffs out. Even if the branch didn't go to primer or past, it probably went through the clear coat. If it went through the clear coat, you will need to be painted. I wouldn't mess with it if I was you, take it to your local high end detailer and he will be able to tell you if he can get it out. It wont cost that much if it can be done, and they are responsible if they buff through your paint.