[Redmi K20 Pro / Xiaomi Mi 9T Pro Guides, News, & D] Robbo.5000:
Considering this guide was written before the Mi 9T Pro was released, it's time to rewrite it and make it more relevant.

THE BASICS

GETTING PREPARED

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If you want to tinker with your phone then you'll need some ground work.

If you don't yet have a Mi account, go to https://account.xiaomi.com/pass/register and create a new account. It is important, when unlocking the bootloader, to have your correct phone number registered on your account, so either choose to create the account using a phone number or add the phone number in the security settings of your Mi account afterwards. Make sure the number is verified by the OTP that will be sent.

Make sure you have adb and fastboot tools installed on your PC. These are part of the Android development tools. You can either install the official Android SDK Platform Tools which can be found here https://developer.android.com/studio/releases/platform-tools

Or you can install only adb and fastboot from this xda members project, called minimal adb and fastboot. https://xdaforums.com/showthread.php?t=2317790&p=42407269

If you want to know more about these tools then read the minimal adb and fastboot post, you'll find a couple of links that explain both tools in detail.

Install the Mi Unlock Tool. You can find this in the guide I've linked to in the bootloader unlock section below.

Install the Mi Flash Tool. This can be found in the guide I've linked to in the MIUI fastboot flashing section.

Install the drivers for the phone. This is done automatically the first time you connect the phone to PC, so go ahead and connect your phone to your PC and wait until it says the phone is ready for use. At this point the computer should identify the phone correctly as a Redmi K20 Pro.

UNLOCKING THE BOOTLOADER

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I'll point to 2 guides, both on the new, official Mi Community Forums.

https://c.mi.com/thread-2262302-1-0.html

This first guide is somewhat incomplete, but it does give some good extra information about the bootloader unlocking and has direct links for the Unlock Tool and previous versions. Sometimes using an older version of the tool will resolve unlocking issues.

https://c.mi.com/thread-1857937-1-0.html

This second guide is more complete, but not so well written. Again there is some useful extra info included.

CUSTOM RECOVERIES

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If you want to flash a custom ROM or root the phone, then you'll need to install a custom recovery. Your only realistic option here is TWRP, however TWRP comes in many flavours. (Before anyone corrects me and says what about Orange Fox? This is, underneath it all, still a heavily modified version of TWRP) For a brief overview of what TWRP is, I'll point you to the official TWRP page which answers that very question https://twrp.me/faq/whatistwrp.html

I should point out that MIUI will check on every boot whether the recovery partition has been modified. If it thinks it has, then the boot process will automatically restore the system recovery. In order to keep TWRP you will need to either flash a custom ROM, or make MIUI stop restoring system recovery on boot up. The most common way to keep TWRP with MIUI is to install Magisk.

If you are planning on using custom ROMs, then I would recommend the official TWRP, or the current 'dev' version from the official maintainer both are found here.

https://xdaforums.com/k20-pro/devel...icial-twrp-xiaomi-redmi-t3944363/post79823568

If you plan on sticking with MIUI, then there are a number of TWRP options that have additional functionality specific to Xiaomi devices - e.g. MIUI debloat scripts.

Many of these tend to be from Chinese, Russian and Indian developers, where Xiaomi phones are most popular. A selection of them can be found here.

https://xdaforums.com/k20-pro/how-to/redmi-k20-pro-firmware-10-3-8-0-9-6-13-t3939647/post79726515

Personally I don't use MIUI so haven't used these much, however OrangeFox seems to have some unique extra functions, like being able to survive OTA updates. So I would guess OrangeFox should be the one to recommend for those that choose to stick with MIUI.

ROOT

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Magisk has become the main choice for rooting, so use it. If you have problems with root and you're using something other than Magisk, you're going to struggle to get any help.

Magisk also does so much more than root. Check out the very good official documentation here for all you need to know.

It includes flashing instructions, which is the same whether you stick with MIUI or have a custom ROM. https://xdaforums.com/apps/magisk/official-magisk-v7-universal-systemless-t3473445/post68966662