If your carrier blocks the tethering you will have to use an APP.
The one that will most likely work is FoxFi. You will need to download it to your phone. If your carrier block the download you can got to the FoxFi site and download. Once downloaded run it and it will make your phone a hot spot with which you can connect via WiFi.
If this APP does not work most likely your carrier has locked the phone from doing any tethering.