Hi I’m a professional piercer so first of all if your septum is still fresh amma need u to go wash your hands and wear gloves if u dont got them its fine just make sure your hand isn’t shaking and sweaty cuz it wont help, slightly move your piercing jewelries to the opposite direction of of the fallen ball grab the ball and put the hole inside the jewelry and slightly press and twist clockwise till u feel the ball grabbing on the jewelry and done
About the size ,it should be a size of 16g or 18 g it shouldn’t be too big so it wouldn’t apply any heaviness on your nose (16g is a size of a round 1.2mm or a size of your index nail it’s small)
Y'all I don't know where the fuck else to go because no one is being helpful I just got my septum pierced like three days ago and I the ball thingy on my jewelry fell of and I can't figure out for the life of me how to screw that little bitch back on and how do you know if the jewelry is the right size cause the person who did it was not a professional