Galaxy s6 ldu root methodology needed... The dummies version

Please could someone help me I have a Galaxy S6 which is an LDU that I would like to root so that it stops wiping every hour or so. I am completey clueless and I really need to get it done but, I don't know where to begin. The model is G920X

Here's the info of my current rom:
Android 5.1.1
G920XXXU1COH3

If you need any more information just let me know please. Thank you sooo much