If you have one shoulder of a trailer tire showing more wear than the other as seen here,
You probably have Camber Wear. Unlike the front end of your car or truck few RV trailers have alignment that can be adjusted with hand tools. BUT the first thing you need to do is confirm you are out of alignment
Assuming that the axles are still firmly bolted to the trailer frame and there are no obvious bent or damaged spring shackles you might need the help of a professional RV Trailer Alignment shop as seen in THIS video.
But you might want to first confirm that you even need to have the axle replaced or "bent".
You can measure your Camber and the Toe-in.
How to measure TOE at home. This video is not of an RV trailer but it does a good job of showing how to be sure the axle is square. While this is on a car you should be able to see that we are looking at having the front and rear of the two tires on the same axle being the same distance apart.
Here is another trailer having the axles measured
I tried contacting Lippert to learn the alignment specs for Camber and Toe but they would not give me the information without providing the VIN and other info on the trailer. I don't understand this as logically Camber should be near 0° and Typical toe-in specs vary from one-thirty-second to one-eighth-inch with closer to 1/32" being better for tire wear.