[Redmi Note 2 Q&A, Help & Troubleshooting] mckennal:
For everyone asking for detailed instructions, (I've tried to simplify so this is not quite exactly what I did). Do this at your own risk, I'm no expert:

1. Boot phone to usual android system. Enable USB debugging by going to Settings -> About Phone -> tap the miui version 7 times

2. Connect to windows computer with USB cable.

3. Download http://bigota.d.miui.com/tools/xiaomi_usb_driver.rar

4. Open "Device Manager" on windows look for a question mark over "MTP" device or similar, right click "Update driver" and search for an unzipped directory of: xiaomi_usb_driver.rar. This step also installed adb driver

5. unzip AndroidSDKSlim.zip to c:\something (search XDA or google, or get official Android SDK from Google's android dev site)

6. Copy recovery.img (extract from the TWRP_recovery.zip from here: http://en.miui.com/thread-146299-1-1.html signup required, rename twrp_ported_from_htc_e9-mt6795m.img to recovery.img) and SuperSU (https://download.chainfire.eu/696/SuperSU/UPDATE-SuperSU-v2.46.zip) into c:\something\android-sdk-windows\platform-tools\

7. Open Admin privilege Cmd.exe in c:\something\android-sdk-windows\platform-tools\

8. Boot phone into fastboot mode by pressing volume down (-) key and pressing power key simultaneously, and then releasing power key. Should see a cartoon with "FASTBOOT" written

9. In the cmd prompt type "fastboot devices" and make sure it lists a device. If not, you have a driver problem

10. type: fastboot flash recovery recovery.img

11. type: fastboot reboot (see step 13 - remember to hold volume + and power when rebooting)

12. Boot into TWRP recovery by shutting down and starting with volume UP (+) held and power (Once TWRP is booted, TWRP will patch the stock ROM to prevent the stock ROM from replacing TWRP. If you don't follow this step, you will have to repeat the install.)

- allow TWRP to modify the system partition so it can make sure it doesn’t get overwritten (swipe right)

- go to TWRP settings and turn off the screen timeout in the settings-->screen of TWRP (prevents hang)

13. Make sure you can copy files to the phone while in TWRP recovery using windows explorer before wiping

14. Go to TWRP -> WIPE and do a full WIPE of Data and Cache partitions and dalvik (not SD card, not system) - this is a factory reset

- to make it super clean I wiped internal sd card as well

- go to advanced wipe dalvik, data, internal storage (internal sdcard), cache

15. copy xiaomi-eu rom (I used: https://www.androidfilehost.com/?fid=24269982087005443 - be sure to check md5 of downloaded file) and official supersu to internal storage of phone using windows explorer

16. Go to TWRP -> Install and choose the xiaomi.eu ROM zip file you downloaded and flash it (you may have to do this twice as after a full wipe it fails the first time, but I didn't)

Took about 2 minutes, doesn't look like it's doing anything, just be patient.

17. Flash SuperSU (official) using TWRP. "Install" then choose UPDATE-SuperSU-v2.46.zip (this step is to give you a rooted phone that works with titanium backup etc)

- TWRP asked if I wanted to wipe caches (dalvik and cache) and I said yes and swiped

18. Reboot to system, wait up to 10 minutes for first boot (or longer, be patient!)

done

I have read simpler ways that don't involve using TWRP, but this is the method I used as I wanted to end up with TWRP.