I would like to know how the lung lavage is done and recovery time.

There are varying degrees of lung lavage and used in two diagnoses as far as I know and involve washing out the lungs with saline or mucolytic agents.

Bronchopulmonary lavage therapy
Bronchoalveolar lavage

Has your doctor recommended that you have this done? I don't know about the recovery time. It would depend on each individual. Maybe you can give us more information regarding your medical diagnosis from your doctor.