They are usually held into the black base by tabs on the clear part. You can usually squeeze the long edge down on one side of the clear part to pop out. Some will have a small slot you insert a screwdriver into to pop them out.
Here's an answer at etrailer.
https://www.etrailer.com/question-152871.html
I'm betting you could find a video if you search enough
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Scott and Liz - Southern NM
2012 Wildcat Sterling 32RL - w/level up (best option ever)
2007 Chevy 2500HD Duramax
Reese Fifth Airborne Sidewinder