S60 headlights

Hello to each other, I have removed the left headlight of my S60 from 2002 and would like to remove the headlight glass from the housing, as it is always fogged from the inside. I have removed the metal clips connecting the glass and housing, but the glass does not leave easily. I do not dare, however, because I fear that I will damage the glass. Has someone successfully and without damage the glass separated from the housing? Is this possible at all or si Is there a typical flaw in the humidity in the headlight? Neither the glass nor the housing are damaged. Greetings from Braunschweig Martin