Now for something completely different: swapping the axle and adding electric brakes.
The original axle was a "drop" axle, meaning the spindles (the bit the wheels bolt on to) are about 4" higher than the axle beam. This is a good thing for normal cargo trailers because it's easier to get heavy stuff into a lower trailer.
I, however, plan on taking this thing on rough off-pavement roads, and don't like the idea of scraping my back end on rocks every time I take a little dip. So I bought a straight axle, as well as some brakes, and swapped them out yesterday.
Jack the trailer up onto jack stands. (Use a real jack to lift it, not the stands themselves!)
Pop the old u-bolts off. You can see the "drop" in the axle.
Pop the new axle on, with new u-bolt kit. Hit everything with some paint.
Follow the instructions (aka youtube videos) to install the brakes.
Pop the wheels back on and admire the new ride height.