If you can’t be bothered to explain then I certainly don’t care sufficiently to google what you’re trying to do.
There are any number of things you can “unlock” on a phone, most of which have nothing to do with the carrier restriction. Hence, the reason I asked was to check that you hadn’t misunderstood something (reasonable if you’re asking for help) as it would be pointless helping you through rooting the phone if it wasn’t actually going to achieve what you thought it was.
If the phone is carrier locked, the best course of action 99% of the time is to contact the original provider and ask them to unlock it. No rooting, no hacking, no market traders, no codes off eBay, just ring Three.
But if you’ve got your “does no-one read any more” grumpy trousers on, then I’m out. Happy rooting.