How to use Dirty COW exploit?

I got Sony Xperia M4 Aqua with a locked bootloader, Android 6.01, and July 1, 2016 security patch, but no DM verity. I would like to freeze a few factory apps via ADB's pm disable command (or any other way possible). I've tried to run su pm disable package.name but the su command is not recognized for some reason. I am a Linux noob but I got Android Studio with SDK and NDK installed on a lubuntu machine (got it also on Windows 7 machine). Can someone explain to me the steps to take in order to gain root shell access with the Dirty COW exploit (or any other way) to be able to freeze apps?