How to get rid of pneumothorax?

Depends. Small pneumothoraces will get better on their own ... If 10% collaps of your lung, estimate 10 days before gone ... 20%, 20 days. If having shortness of breath, or if pneumothorax getting bigger, then need some type of catheter or tube inserted into the chest to evacuate the pneumothorax until the air leak resolves.
Pneumothorax. Depends on size; larger ones need chest tube very small ones can resolve on their own important to get serial exams.