If you are planning to unlock your Google Nexus 5X Bootloader, here is how you can do it on your own. Be warn that your phone might get brick so do it at your own risk.
Start by going to setting and click on “build number”. Click until you get to the notification about you enabling the Developer Option. Press Back to go back to Setting > Developer Option > Enable OEM Unlock and check the box. Also, enable the USB Debugging while you are there. Now enter Bootloader by holding down on the Power and Volume Down button. Connect the Nexus 5X to your PC.
Next open the command prompt by locating the Fastboot.exe and shift right click in that folder to open the command prompt. Now, type in the code “Fastboot devices”. This will tell you if your drivers are install correctly.
Next, type in “fastboot oem unlock”. Confirm the action. Once the process is complete, type in “fastboot reboot”. Once that is done, disconnect your device and you should be done.