I still use my old 1978 Truckers special 12t hyd bottle jack. It has a 10" X 10" base made for side of the road use. Long jack handle easily slides the jack under the axle tube next to the U bolts. It came with a adapter that cradles the axle tube. Its jacked 1750 lb on up to 11000 lb axles on loaded trailers. I just had it repacked for the 3rd time since '78.
As one poster say just jack one end of the axle just enough to get the spare back on. That way I'm not lifting the whole side of the trailer.
What ever method you use do a dry run at home especially with those drive on blocks. Lots of members over the years found out they didn't work with their trailers suspension.