First ill explain the situation and hopefully someone will be able to help me out. I do currently have an unlocked and perfectly fine 8gb iPhone working on Rogers here in Ottawa. Its my life (in addition to my MacBook) I talk on this phone everyday and text like a fiend. I dont want to do anything to make my phone stop working.

now heres my question.

my phone is running 1.0.2 (old school i know) and i was wondering what i would use to take this currently perfectly fine phone (only running old firmware) and update it to 1.1.3. I downloaded ZiPhoneOSX im just skeptical about what it will do.

Above all i dont want my phone locked again if I cant unlocking again easily.
Any help would be fantastic. Thanks