I've done the spings on two moho's and a few trucks. Main thing is to have 2 floor jacks, and 4 jack stands that can handle the weight of the moho. While it looks intimidating, it is really pretty basic. Jack up axle, remove tires, stand the coach body, loosen ubolts, let down axle until ubolt shows movement, then finish removing ubolts and stand axle. Jack up spring slightly to remove spring bolts. Wrassle out spring and take to shop.
Everything is real big, so it is scary, but it is not a real hard thing. True, the springs can be a bit heavy, but not impossible to handle.
After the last set was installed, I pried the end of the springs apart and stuck pieces of radiator hose over the ends to keep them from rubbing and making noise. Not sure where you are at, but a good spring shop can re-arc your current springs for a nominal price and can add a leaf if you want. Don't know if there are any spring shops in your area, you would have to look. If you add leafs, add the same number to the front as well as the rear.