You might see what they want just to rearch the 2 main leafs. you can C clamp the spring aways back from the center bolt on each side of it then remove the nut then evenly undo the clamps & save yourself some labor & as said adding a leaf is doable. I like to remove the nut with a nut cracker if it is tight rather than risk breaking the special bolt tho the spring shop would carry them. just for reference before starting I would jack up the rear & with your tape see how many inches of increased height you are after. If you go with new springs I would get 1" over stock height. EDIT if adding a leaf you may need center bolts with more threads