Can I buy other phones than the Nokias on the speakout website? | Phone/Device Issues and Features | Consumer forum

I would start by reading the SIM card guide. As for doing the actual unlocking of a phone (once you've determined whether or not it needs to be unlocked), it's usually done either by entering a code into your phone or by connecting your phone to a computer and using software to unlock it. This might be free or you might have to pay someone to do it depending on the phone.