How do I open my phone bootloader

[Peppul]

Am not an expert in computer programming,am just a regular guy. Just recently acme in contact with the world of custom roms and rooting. Saw some custom roms for my xiaomi phone which I love but don't know how to go about it. I was told to first open my bootloader before I can start installing custom roms, so I wanna ask you guys. 1. What are the steps required.
2. What are the things I need.
3. What is the easiest way to open a bootloader.
4. And do I need to be an expert before I proceed. Thanks

 

[Sheun450]

How to unlock bootloader (Android) · Install ADB and Fastboot on your PC · Enable developer options by navigating to Settings - About phone and clicking on "Build number" seven times. · Go to developer options and enable the button

 

[Kaffyfolla]

To unlock the bootloader and enable partitions to be reflashed, run the fastboot flashing unlock command on the device. After setting, the unlock mode persists across reboots.

Devices should deny the fastboot flashing unlock command unless the get_unlock_ability is set to 1. If set to 0, the user needs to boot to the home screen, open the Settings > System > Developer options menu and enable the OEM unlocking option (which sets the get_unlock_ability to 1). After setting, this mode persists across reboots and factory data resets.

When the fastboot flashing unlock command is sent, the device should prompt users to warn them that they might encounter problems with unofficial images. After the user acknowledges the warning, the device should perform a factory data reset to prevent unauthorized data access. The bootloader should reset the device even if it can't reformat it properly. Only after a reset can the persistent flag be set so that the device can be reflashed.