How to Swap iPhone SIM Card?
you cannot simply swap sim cards unless the phone is unlocked..you can get your Iphone unlocked using remote unlocking method that ll be available at any commercial vendors online like Classicunlocking.com …
To put in a sim card in your unlocked iPhone, get a paperclip. Press straight and down into the SIM card holder hole. (Some iPhone 3GS, iPhone 3G box might contain a SIM eject tool, but a paperclip would do). The first time you put in an unofficial SIM card it might take a minute to recognize. Instead of “No Service” your iPhone should display your SIM card carrier (such as T-Mobile) when the new SIM card is recognized.