Devius

I thought I'd get some advice before I went out and experimented on my own. I recently had my driver's side headlight worked on by the dealer because the light kept turning on and off. They corrected the problem, but the light is a little loose in the housing. How can I tighten it back myself? If I push on the headlight it moves a little, where as the right side headlight doesn't budge. Is this something I can fix or should I let the dealership fix it?

Thanks!