Instructions are here: CF-Auto-Root by Chainfire
It uses ODIN to flash SuperSU but keeps the stock recovery and does not install a custom recovery (CWM or TWRP). It keeps the ROM as close to the stock version as possible.
When selecting a CF-Auto-Root file from autoroot.chainfire.eu, select the SCH-R530U (US Cellular variant) to substitute for SCH-R530M (MetroPCS variant).
It uses ODIN to flash SuperSU but keeps the stock recovery and does not install a custom recovery (CWM or TWRP). It keeps the ROM as close to the stock version as possible.
When selecting a CF-Auto-Root file from autoroot.chainfire.eu, select the SCH-R530U (US Cellular variant) to substitute for SCH-R530M (MetroPCS variant).