Guide : How to write a new .prl to v-iphone 4 without open ssh-(the simple way)

[calisoldier83]

Is there any advantages on doing this if i already have cricket on my i phone 4, with redsnow jailbreak? sorry new to the i phone game

General question: so if you change the carrier settings on a jailbroken phone, then you install an update without jailbreak will the phone revert back to original settings?