Clearance light, tail light, or porch/utility light?
The clearance lights are one unit, the light pushes into the back. You have to remove the two screws, remove the light from the trailer, and turn it on the rubber socket. Then you can access the light and change the bulb. That said, the front and rear lights are both covered on top with Dicor roof sealant, to prevent water from seeping behind. The foam gasket isn't really sufficient long term. So if you remove these, you'll need to scrape off the old, and replace with new. Don't use silicone, only use the Dicor 501 sealant. You could use the Dicor 551 non-self leveling, but you can't use that on your roof if you have any spots needing touch up. In terms of LEDs, not all LED bulbs will fit these lights, since they are pretty shallow. Many of the eBay ones are very tall. I put LEDs in all the clearance lights of my '97 and used Sylvania bulbs from Autozone/O'Reilly. They aren't cheap, but they are compact and fit well in the light housing without any modification.
The taillights are easy- two tabs hold the lens on. Take a screwdriver or something small and thin and push on the white plastic tab on one side of the light. Don't push too far or you might break it off. Push just enough to release the lens.
The porch lights are tricky, I've never had one off, but supposedly there's a trick to getting the lens off. JohnB explained it somewhere here.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9467.8 (as of 5/26/19)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR