I bought a truckers special shorty 12 ton hyd bottle jack in the '70s when I was on the road pulling GN trailers. It was made specially for trailer axles with a adapter that cradled the axle tube....and came with a 10" wide base for soft ground....and a 36" handle.
Simply slide it under the axle next to the U bolt and raise one end of the axle just enough to get the spare back on.
If I need one side of the trailer raised it will do that also.
I use it for the truck also.
Whatever method you choose make a dry run at home. Lots of newbys bought into the trailer aid thing and found it wouldn't raise the flat tire enough to change.
Or they didn't have enough cribbing or jack to raise the whole side of the trailer.