HTC One M8 Verizon to Stock ROM with RUU Flash With CMD or SD Card Flashing

First Need : Bootloader Unlock 

Warning:

The RUU installation procedure is considered risky and though it has been tested successfully, we do not hold any responsibility. The device is yours and so are the risks involved!

Preparations:

• Make sure your Verizon HTC One M8 is S-OFF’d. If you have not done this yet, you can easily S-OFF your VZW M8 using Firewater method (it has been discontinued).
• Install HTC Sync or HTC USB Drivers on your computer: Download here
• Enable USB Debugging on your phone from Settings> Developer options. If you do not find Developer option under device settings, read the instructions given here.
• Download and setup Android SDK on your computer so that you have a working ADB and Fastboot.  If you new to such things, you can refer to our guides on the topic: Guide 1, Guide 2
• Download the stock RUU file in Zip for the Verizon HTC One M8: 0P6BIMG.zip (stock pre-rooted KitKat 1.55.605.2)
• Go to Settings> Power and turn off Fastboot option.

Restore Verizon HTC One M8 to Stock

So you think you have made all the preparations mentioned above? Great! Now here are the instructions to restore Verizon HTC One M8 back to stock ROM.

Method 1

1. Download the RUU file and copy it the Android/sdk/platform-tools folder where ADB and Fastboot files are located. The location of this directory depends on where you have installed the Android SDK.
2. Connect your Verizon HTC One M8 to computer via USB.
3. Move the mouse pointer to an empty space in the platform-tools folder and then press Shift key+Right click on the mouse. Select Open command window here option to launch cmd prompt.
4. Just to make sure that you have set up ADB properly and your computer can communicate with your phone, type the following command in the cmd window and press Enter key:

   adb devices

5. If you see the serial number of your device on the cmd, all’s fine. If you get some error message, you need to check your USB drivers and ADB setup again.
6. Now reboot your HTC One M8 into Bootloader mode. You can do it using Volume Down+Power keys manually, or by issuing the following command:

   adb reboot bootloader

7. When you get on the bootloader screen, scroll to FASTBOOT option and select it using the Power button. To test Fastboot, type the following command in the cmd:

   fastboot devices

8. Since we are using a RUU file to install the stock ROM, boot the device into RUU mode. To do this, simply type this command:

   fastboot oem rebootRUU

9. When your phone is in RUU mode, you’ll see the HTC logo on the screen.
10. Okay, it’s time now to install the RUU file. Just type the command given below. Please note that the red text in the command line is the name of the RUU file. If you have an RUU file with a different name, you’ll have to replace the red text with the name of the file you have.

    fastboot flash zip 0P6BIMG.zip

11. Now you’ll see a green progress bar at the bottom of the phone’s screen showing installation status.
12. Now throw your eyes on the output message on the cmd window. If you see any message asking you to reboot or flush, issue the following command and start again from Step 7.

    fastboot reboot-bootloader

13. When you get success/finished message on the cmd, you can reboot your device by typing the following command:

    fastboot reboot

14. Wait till your HTC One M8 boots up.

Method 2

If you find the Method 1 too complicated for you, we got a much easier way of installing the stock ROM back to your Verizon HTC One M8. The following method is also suitable for those who do not have access to a computer. However, the is one step when you might need a computer.

1. The method requires an external SD card. If you already have it format it to FAT32. This is actually the default mode of formatting memory drives on Windows.
2. Now copy the RUU file (0P6BIMG.zip) to the memory card.
3. Reboot your HTC One M8 into the Bootloader mode by pressing and holding the Volume Down and Power buttons for 2-3 seconds.
4. Your device will automatically detect the RUU file and you’ll see installation prompts on your phone’s screen.
5. Just follow the onscreen instruction and the RUU will be installed to your device within a few minutes.

Congrats, you have successfully restored your Verizon HTC One M8 to pre-rooted stock ROM with stock recovery! Do not forget to share you experience with the RUU installation procedures described above. Cheers!