How do I remove it without opening the housing again?

 

it will self-dry as the moisture drips out a drain hole/wire pathway on the bottem
You may be able to fix with silicone seal on the outside of seal edge
and dont use a pressure wash on the headlight area

BUT
that moisture drips out, then hits the ballast and fries it!

Once you have moisture, you may as well plan on replacement of ballast-ignitor and bulbs--do both sides
a good kit from hidextra is only $59!! U$D unreal low price and in use by many on here without problems

 

Fix the moisture problem as soon as you can or you will face other major problems with ballast and other related items.

 

good ol Silicone seal applied along the lens seal to housing should take care of you

beyond that, dont use drive thru/quarter car washes- high pressure water will make its way inside the lens again

 

Condensation killed my xenon lights and they're a pain to replace because mine need a security torx head. It'll kill the light so take it off, dry it out and silicon sealer. I had some lying around from other repairs but any good waterproof sealant for cars will work. Use it on the back and you'll be good to go.