Default Unlock XT925 to use with other carrier

Hi everyone, I want to unlock my phone to use it with another carrier. I'm ending my contract soon, my phone is from Claro and I don't like their service, I'm thinking on switching to Net10. Since my phone is already a GSM, what should I do to unlock it? Unlock code? I've seen a few pages but don't seem trustworthy. Also, do I have to flash modems to get LTE or this is only with the CDMA XT926? Any help will be appreciated.

Sent from my XT925