... GSM version (Maguro) with Android 4.3 from GNU/Linux

I found so many incomplete tutorials written in bad English that I decided to write one myself and keep it simple. You must have your phone’s bootloader unlocked; doing so will wipe your device!

1. Watch this tutorial video.
2. Download the fastboot and adb binaries, e.g. from the Universal Nexus Linux Toolkit. Extract the archive on your machine. Find the binaries.
   The problem with this toolkit is that the bundled zips are rather old and didn’t work for me, so:
3. Download the ClockworkMod recovery image from here.
4. Download the SuperSU zip file from here.
5. Connect your phone to your PC via USB.
6. Boot your phone into bootloader mode: Power it off, push both the volume rocker up+down and then press the power button, i.e., press all three at once for about two seconds.
7. ./fastboot oem unlock if you haven’t ever done it. This will wipe your device, reset it to factory settings and delete all your data. Yes, really.
8. ./fastboot flash recovery /path/to/recovery-clockwork-6.0.4.7-maguro.img
9. Now load the recovery: Volume button down twice to choose Recovery mode, power button to select.
10. Navigate using the volume rocker: “install update from zip”, press power button to select, choose “install zip from sideload”, press power button.
11. ./adb sideload /path/to/UPDATE-SuperSU-v1.93.zip
12. Navigate back and reboot normally. Your installed apps should now show SuperSU installed.

Have fun!