You need to ask Xiaomi for permission first.
Then when permission is granted, you have to wait a few days to unlock the bootloader using the official unlocking tool.
Download the MIUI Forum app from Google Play store.
Open the app sign in or sign up.
Search forum on how to unlock bootloader.
Follow the instructions given.
Flash and enjoy any ROM available for your device using the correct flash tool.
Kindest regards.
Thanks for confirming...and I guess that your device is rooted.
Therefore you can attempt to remove them but do a local backup before you proceed in case something goes wrong.
Kind regards.
Sent from my Redmi Note 4X using Tapatalk