That is in fact how you change CSC. Doing that will completely wipe your device so be careful. It looks like you got an unlocked phone with the MTS bloat built in instead XAC CSC.
yo dude i tried changing my csc from FMC to XAC but it didnt work. I selected XAC but after it wiped my phone it said its still FMC. My phone was locked previously but I just unlocked it recently. I just want to get the fido bloatware off my phone. any tips?