Odin3 v1.85

Odin is the most used and probably best software to change your smartphone ROM or firmware, root it and it helps you do pretty much everything you want with your phone. Odin 1.85 is really simple to use, but you need to be very careful when changing settings, because if you tick a wrong checkbox you can damage or even brick your device. If you don’t know how to use Odin, then you need to read a guide and fortunately there are guides for virtually every smartphone on the market.
There are a few pieces of software that allow you to flash ROMs on your device, but Odin is the most used one and most rooting / updating guides teach you how to do it using Odin, so it’s recommended to download it.