Install Official Android 8.0 Oreo Open Beta Rom on One Plus 3/3T

REQUIREMENTS :

• Download OxygenOS Open Beta 25 for the OnePlus 3 and 16 for the OnePlus 3T 
• Click here for OxygenOS Open Beta 25
• Click here for OxygenOS Open Beta 16

How To Android 8 Oreo on One Plus 3/3T :

• For safety backup your files before installation
• If you are on Stable Rom or Open Beta Rom then copy the downloaded beta rom and paste it to your phone directory
• Now open Setting/System Updates

• Then click on the Setting icon on the top right corner

• Now click on Local Upgrade
• Installation will start and it will take around 15mins