If you want to get your phone unlocked, first call your carrier. Some carriers will require you finish your contract before unlocking your phone. But some carriers, like Verizon will unlock your phone as long as you've had your phone for 30 days or more and you don't owe them any money. They may be more lenient if you plan to use your phone while traveling to another country. This is true if you have a "world phone" from Verizon or a GSM phone. As far as the 4g/4g LTE goes, that may or may not be true.
