Sounds like you are describing what is often called SMD (surface mounted devise) which are LED that are mounted more or less permanently on a surface as a way to make them small. The problem is that most of have very little chance of getting them off and replaced as an LED, so we need to change the whole fixture, or at least the board they are mounted on.
Looking at the parts drawings, I see these listed as having several parts, so possible to replace just the part with the LED mounted on it? Possibly only need the first item?
I suggest doing a search using just the part number, to see if there are alternate sources online as a way to compare prices and service, then I might also contact some of the big name Winnebago parts places to see what they offer for the part I need.
They will likely come up in your parts number searching?
Or shortcut the process and go straight to Lichsin as a pretty sure bet of them knowing far more about the issue?? I can guess while they often know!
I might add that the reason they have failed may be due to water getting in, so I might want to check for better sealing, maybe even caulk around the top and sides?