I am in the process of replacing the lift and turn stopper in my bathtub. I went and bought a drain key to take the stopper out. My problem is that some of the stopper came out and some didn't. There is still some metal stuck to the threads of the plastic elbow under the tub. How can I get the metal out of the plastic threads without ruining them ? I thought about just replacing the elbow, but that would require tearing out part of my downstairs ceiling, which I don't want to get into. I've been trying to get this metal out of the plastic threads all day. :-( PLEASE HELP ME! :-)

Skinny, flat screwdriver and keep pushing it outward ( like unscrewiing it)...

Can you take a picture of it and post it ? Take a close up, too... Thanks