If you rotate the ceramic piece to the left or the right you will be able to screw the post back in place . It has moved a little and is not lining up with the threaded hole . No need to take your atomizer apart you can soak it in alcohol or boil it if your worried about germs or it being dirty .
I should also mention once you have the negative post unscrewed the whole ceramic deck can be pushed out from the base of the atty
I should also mention once you have the negative post unscrewed the whole ceramic deck can be pushed out from the base of the atty