Earlier today, OnePlus released the first build of OxygenOS for the One. The ROM is pretty much a stock build of Android 5.0 Lollipop with some features and customization options thrown in. 

If you cannot wait for CyanogenMod 12S to come out, you can install OxygenOS on your One, but do note that the ROM comes with substantially less features and customization options than CM11S. If you don’t mind losing a few features to try out Lollipop, you can follow the steps below to install OxygenOS on the OnePlus One.

Note: Installing OxygenOS will not void the warranty of your device. However, installing the ROM requires you to unlock the bootloader of the handset, which in turn will wipe out all your personal data from the phone.

Therefore, it is recommended to make a backup of all your important data before proceeding with the steps below. In case the bootloader of your One is already unlocked, you will not have to worry about losing your music, photos and other important documents.

Unlocking the bootloader

Step 1: Download the ADB/Fastboot files from here (Mac), extract its content and transfer them to a folder called “one” on your desktop. Also, download TWRP recovery image from here and transfer it to the same folder.

Windows users will also have to download and install the ADB/Fastboot drivers on their system.

Step 2: Reboot your OnePlus One into fastboot mode. To do so, switch off the handset first, and then press the power button and volume up button simultaneously.

Once the fastboot logo comes up on the screen, connect the handset to your PC.

Step 3: Now, depending on whether you use Windows or OS X, open up a command prompt or Terminal window and navigate to the “one” folder on your desktop using the ‘cd’ command.

Alternatively, you can also drag ‘n’ drop the “one” folder to the terminal or command prompt window to open the directory directly.

Step 4: Make sure that the device is being detected by your PC by entering the command below.

fastboot devices

Mac owners will need to prefix a “./” before every fastboot or ADB command, so the above command will look something like this on your Mac:

./fastboot devices

Step 5: Now, unlock the bootloader on your One using the below command:

fastboot oem unlock

For Mac:

./fastboot oem unlock

Make sure to confirm the selection by pressing the Volume up button on your One. Once the bootloader is unlocked, your handset will automatically boot back into Android. You can skip the setup process for now, since you will end up installing OxygenOS anyways.

Install TWRP recovery

Step 6: Download OxygenOS from here, extract the ZIP file present inside it and transfer it to the internal storage of your handset. Then, again boot your One back into fastboot mode by following Step 2 from above.

Step 7: You now need to flash TWRP recovery on your One by executing the following command:

fastboot flash recovery <insert twrp recovery filename.img>

On a Mac:

./fastboot flash recovery <insert twrp recovery filename.img>

Installing the OxygenOS ROM

Step 8: Disconnect your One and switch it off. Then, boot the handset into recovery mode by pressing and holding down the Volume down key and the Power button simultaneously.

Step 9: After your OnePlus One has booted into TWRP recovery, tap on the ‘Wipe’ option. Select ‘system’ and ‘data’ partition and then confirm your selection by swiping the arrow at the bottom to the right.

Step 10: Once the partitions have been formatted, select the ‘Install’ button and navigate to the folder where you had transferred the ZIP file of OxygenOS. Confirm your selection by swiping the arrow on the bottom to the right.

Step 11: Once OxygenOS has installed, select the ‘Reboot system’ option in TWRP recovery.

Your OnePlus One is going to take sometime to boot into OxygenOS for the first time, so don’t panic if the phone seems stuck on the boot logo for a few minutes.

In case you are facing any issues while installing OxygenOS on your OnePlus One, drop in a comment and we will be happy to help you out,