HTC One M9 just received custom recovery support from TWRP 3.0 in preparation for Android 6.0.1 Marshmallow. TWRP 3.0 custom recovery is promised to support a host of exciting features that will allow One M9 owners to expand beyond any official firmware can offer.

TeamWin developers have created the latest version TWRP 3.0 custom recovery which is filled with a slew of tweaks that include big design overhaul, source code update to Marshmallow and a few more.

Before installing TWRP 3.0, the following reminders and prerequisites have to be noted first:

1.      Unlock HTC One M9's bootloader here.

2.      Install HTC Sync with full working ADB and Fastboot tool.

3.      Do not use the custom recovery to other devices.

4.      Connect the device to any PC using a USB driver. Download a driver here.

To begin with the installation to HTC One M9, here's a step-by-step guide:

1.      Configure ADB and Fastboot in the PC here.

2.      Connect phone to PC using the USB cable.

3.      Copy then paste downloaded ROM files to phone's memory or SD card.

4.      Download TWRP (twrp-3.0.0-2-hima.img) here and copy/paste it in the android-sdk-windows\platform-tools directory.

5.      Go to Fastboot/Bootloader mode 

6.      Type in: adb reboot bootloader

7.      Press Enter.

8.      Wait for the driver to be installed.

9.      Type in: fastboot flash recovery twrp-3.0.0-2-hima.img

10.  Press enter.

11.  Once completed, select Recovery and enter Recovery mode.

12.  Select "reboot system now" from the recovery menu

13.  Wait for TWRP to be installed.

To verify the update, to go Settings > About phone.