Help unlocking Samsung S4 SPH-L720T with code

[anapana83]

I have a Samsung S4 SPH-L720T (Lollipop 5.0.1) with Boost Mobile and i called them and let them know that i've had the phone for over a year and wanted to use it abroad in central america with one of their local SIM cards. Long story short, they gave me the unlock code for my phone, since i met the qualifications, and they told me that it would unlock it domestically and internationally, and that i just have to take it to whichever carrier i wish so that they can unlock it. However, i was wondering if there was a method or any way one could do it themselves. Or does it have to be done by a carrier rep? I just want the phone for international usage and i'm clueless to this stuff, so any help would be appreciated!