There are good no. of reasons why carriers block the tethering option on your Android phone. And there are still great no. of reasons why we the user hate it. But anyway, we take it you don’t really like the idea of not bring able to share your faster LTE connection with friends, and thus may wanna unlock the ability to tether the 4G network all by yourself. Well, it’s possible and chas123 has shown us the way to do it — you do need root access by the way to be able to do this. And also the custom recovery, either of CWM and TWRP recovery would do.
The process involves flashing a tether-fix zip file via recovery and then editing a specific APN database file cdmaapn.db in /data/data/com.android.providers.telephony/databases folder.
You can find the full procedure at the source link over here.
And, as regards recovery and root, find the help here. This toolkit will guide you all the way, beginning with drivers installation if need be to the successful and adventurous trip of innstalling a recovery and then flashing the superSU file for root access. Good luck!