The HTC One M9 is one of the  top flagships of 2015, wielding a 5 inch screen, a 20 megapixel shooter, and a Snapdragon 810. It contends quite well with the Samsung Galaxy S6 and the LG G4 as a great high-end option. The phone came out with Lollipop 5.0, but 5.1 has since been released. An official 5.1 has yet to reach the thousands of  HTC One M9s in the wild. Fortunately, with Android, such an issue can be solved by the utilization of a custom ROM. MaximusHD is an excellent Lollipop 5.1 ROM available for the HTC One M9, with stability, Sense 7.0 and great battery life. This guide will walk you through easily installing the MaximusHD Lollipop 5.1 ROM.

You will need, of course, your HTC One M9, a PC, and a micro USB cable. Once you attain all three, just follow the process below to install the MaximusHD Lollipop 5.1 ROM.

HTC One M9

There’s no point in attempting to flash a custom ROM on the HTC One M9 smartphone unless you have already rooted it and installed a custom recovery. As time continues to go by, you might find more custom recoveries available. All of you can install the same custom recovery that’s in our guide, though. Those who didn’t enjoy using the Minimal ADB link on the original method to unchain the internal system, might prefer gaining root access using the Squabbi Toolkit.

Furthermore, you can’t unchain the internal system with root access unless you unlock the M9 Bootloader. So, you should follow the link through on how to get that done before starting the root with recovery. Once you have all those things, you are ready to flash your MaximusHD custom ROM using the guide below.

How To Install The MaximusHD Android Lollipop 5.1 Custom ROM On The HTC One M9

1. Make sure your device is unlocked or is in s-off mode. You won’t be able to perform this install otherwise.

2. Download the MaximusHD 5.1 ROM. You may also download Google Apps and flash them after the ROM to have Google’s apps working.

3. Connect your HTC One M9 via Micro USB to your PC.

4. Place the ROM zip file in your M9’s internal SD card partition using your PC’s file manager.

5. Press the volume up button and the power button to turn on Download mode.

6. Now, select “reboot to bootloader”

7. After a few seconds, your M9 will reboot to the bootloader screen. Select “Wipe data/factory reset” from the list of options.

8. Once the wipe is done, locate the option in the recovery called “choose zip from sd card”. Select it.

9. Look for the ROM file you moved to your phone earlier and select it.

10. Follow the steps the Aroma installer provides.

11. Reboot your phone once installation is complete.

You will now be able to experience the refinements brought to Lollipop in the 5.1 update on your M9.