[q] how to s-off topic

Hello guys i need some help, i have the htc one from sprint, i haveto unlock the sim card to use it, id research the last to days and the conclusion was: i need to downgrade my hboot it actually is 1.57, but first i need to be s-off, how do i do that? i need to be rooted? the only ruu that worked for me was the lollipop one, and if i get the s-off how do i downgrade my h-boot? the thing is that i need to be on 4.1.2 to get the old guides to work out(sim card unlock) please help if anyone knows about this:(