how to remove the headlamp assembly . moister inside , need to dry it out .

Hello, Short and sweet: you have to replace the headlight, or have it professionally repaired. They are sealed units, except for the bulb, and once the seal degrades, condensation forms inside.

I had a small amount of moisture in both of my headlamps on my 2013 Buick Regal. I had to have them replaced as they are a sealed unit. The cost was about $900 total for both. Luckily, the car was still under warranty. From what I understand from the tech, Buick has a "percentage" of condensation that is acceptable and they measure it prior to making a determination on whether or not it is covered under warranty.