Here’s how to download and install OxygenOS Android 5.0.2 Lollipop ROM on OnePlus One. For complete step by step instructions, head past the jump.
Do note that while rooting and flashing a custom ROM on your OnePlus One does not void your warranty, any damage to the phone from doing so will not be covered by it.
Unlocking Bootloader and Installing Custom Recovery
Step 1: To begin, download the TWRP custom recovery from here and place the file in the Fastboot folder in the installed Android SDK on your computer.
Step 2: On your phone, enable the installation from Unknown Sources from Settings > Security.
Step 3: To boot the phone into Fastboot mode, hold down the volume up key + power button. When you see the Fastboot logo, you can now connect the phone to your computer.
Step 4: Run Terminal on Mac or Command Prompt on Windows and enter the following command to unlock the bootloader:
fastboot oem unlock
Step 5: Now we will flash the TWRP recovery. Run Terminal or Command Prompt and navigate to the Fastboot folder where the TWRP recovery image is placed. Enter the following commands:
fastboot flash recovery <recovery.img>
The custom recovery is now installed.
Installing the OxygenOS ROM
Step 1: Download the OxygenOS ROM from here and copy the file to the root of your phone’s storage.
Step 2: Now we need to enter recovery mode on the phone. Do this by holding down the volume down key + power button.
Step 3: Once in recovery mode, make sure you take a Nandroid backup. After taking the backup, do a complete factory reset of the phone.
Step 4: Now tap the Install button and look for the oxygenos_1.0.0.flashable.zip file to install it.
Step 5: Once the ROM is flashed, simply reboot your phone.
That’s it! You are now running the latest Lollipop OS based OxygenOS ROM on your OnePlus One.
Here’s an over-the-top run-down of some of the features which OxygenOS ROM comes with.
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