Hi Hans, here's what you do, step by step, from another thread that I posted in.
We're going to use the so-called fastboot method.
1. You need the following software - your phone is a "hermes", if in doubt.
* adb fastboot tools - google, download zip file, unzip to your pc (I use linux, but but it's the same principle for windoze and mac)
* TWRP_multirom-v2.8.4-mocha_signed.zip (you can use others, but this works fine)
* UPDATE-SuperSU-v2.46.zip
* your chosen ROM.zip - I like global beta from here, but you could use any appropriate ROM, such as global 7.1.3 etc - just make sure you have the hermes version
2. Prepare your phone by going to settings/about phone and tap 7 times on the MIUI version. Then go to additional settings/developer options and check usb debugging.
3. Unzip and place only the TWRP image (either called recovery.img or twrp.img, or whatever you like) into the unzipped adb tools folder on your PC. You need not extract the entire content of TWRP_multirom-v2.8.4-mocha_signed.zip, just the .img file. You may overwrite any existing recovery.img in adb tools.
4. Place the superSU and chosen ROM on your PHONE in a suitable location so you can find it later - either at root or in download (for example).
Ready to go? Now we are going to install TWRP to the phone, so you can use it to root and then install the new ROM.
a. Power down your phone. Then, restart by carefully holding the volume down key and press the power button. When you feel the vibration, you can release the power button, but keep the vol down depressed. Your phone will boot into "fastboot" mode - a modified android icon will appear. Now, connect the phone to your PC with a usb cable.
b. On your PC, go to your adb tools folder, right click and open a terminal.
c. In the terminal, type "fastboot devices" - no inverted commas, you should see some indication of the phone being seen (because you are in developer mode as per 2. above)
d. then type "fastboot flash recovery recovery.img" (no inverted commas; use whatever you called the .img in your folder - this assumes recovery.img). The TWRP image will be flashed to your phone using fastboot mode.
Now, you can type "fastboot reboot", or just remove the battery - get your phone to power off mode and unplugged from your PC. You are now finished with your PC - everything else happens with the PHONE only - make sure it is charged or plugged in for power.
Next - we're going to root the phone and then install the new ROM:
1. Power up your phone into the new TWRP recovery which has replaced the MIUI stock recovery. To do this, hold Volume up, then hold in power. When it vibrates (which can take 15 seconds), you can release power button, but it's very important to keep the volume up held in. It does take a bit longer than you think to boot into TWRP recovery - maybe a minute - so don't worry, just hang on with the vol up depressed. Your phone will boot into TWRP and you can start to do the good stuff.
2. Go to install on TWRP and a file list will appear. Navigate to your superSU.zip (wherever you placed it as per 4. above). Select it and swipe right as per TWRP. Clear cache and Dalvik afterwards when prompted.
3. Return to install by back buttoning in TWRP. Repeat the process with your selected ROM.zip, wipe caches and Dalvik afterwards. Note sometimes TWRP seems a bit slow, but just wait - it doesn't take more than 5 minutes at worst to place the files for the new ROM: - the actual installation takes place when you reboot.
[If you are struggling to boot into TWRP, try this - when you have completed the adb fastboot process, leave your phone attached to your pc and type: "fastboot reboot" (without quotes). As the screen goes black, hold in the Volume Up. This will boot to twrp. Rebooting completely uses a system root file that automatically reverts to MIUI recovery, on some (but not all) phones. Later versions of the EU weekly ROm include TWRP 3.0, replacing stock recovery, so this should not be an issue if you have a recent ROM.]
So, reboot your phone when TWRP tells you that you have finished - this WILL take about 5 minutes at best - you can remove battery or otherwise power down. Startup with power button; resist the urge to fiddle until the MI load has happened. The bar that shows progress slows down towards the end of the process, just before you are presented with a beautiful MIUI ROM without any of the super-irritating Vendor shaftware.
When you're up again, check under about phone and you should be up on the new ROM.
Have fun
