How to unlock SCH-I535 for any operator topic

I have a Samsung Galaxy S3 SCH-I535 running Android 4.4.2 Kit-Kat with verizon for USA
but now I'm here in Mexico and there are other operators:
-Movistar
-Telcel
-IUSACELL
and so on

How to unlock it for making it available for any SIM card

Thanks for the support