THESE INSTRUCTIONS APPY ONLY IF THE TELECOMMUNICATION PROVIDER HAS CONFIRMED THAT YOUR IPHONE IS UNLOCKED.
iPhone unlocking steps to follow:
Start by connecting your IPhone to iTunes on your desktop computer, you will see the "name" of your iPhone pop-up under "Devices". Right click on the name of your device and select "Backup".
Once backed up, use your IPhone and go under "Settings" application. Under "Settings", choose "General" and then "Reset". Once in "Reset" you need to select "Erase All Contents and Settings" which will give you a prompt with a button marked "Erase IPhone", which by clicking will complete the hard reset. The phone will power cycle and bring your IPhone back to factory state.
The phone in question will need to be set up as if it was new, select the country, language, etc... this can be done with any SIM card in it, Bell/Virgin or another provider.. Once all is set up, you will be given backup options, one of them being "Restore from iTunes". Once your phone is backed up your iPhone will be unlocked. If you do not get prompted to choose a backup option, then you just need to go back into iTunes, once again right click on your phone under "Devices" and from the pop-up menu, choose "Restore From Backup".
Please note the system may not tell you that the IPhone has been unlocked, please test with a SIM card from another provider.
For more info, you can try this link: http://support.apple.com/kb/HT5014