Are you talking about replacing the spring hangers on the truck or the trailer?
If trailer, it's not a bad job but just make sure you have the necessary jacks and jack stands. On tandem trailers you have to fight with the equilizer a bit to keep it from flopping up or down but once you realize how to support both axles it not too difficult. Also, it's much easier if you have help as the axles are heavy. I did mine by myself as a complete rebuild with new leaf springs, hangers, hd equalizers, u-bolts, etc. Would have been much easier if my son would have been available to help.
Make sure also that you replace ALL hardware you remove, ie, shackle bolts and nuts, u-bolts, etc, etc, as these parts are considered one time use and should not be reused.
If you're talking about your truck, it's even easier.