How to flash Oxygen OS 3.5.2 community build for OnePlus 3

Step 1: Make sure you have all the ADB files installed in your computer and then proceed  downloading the Oxygen OS 3.5.2 zip file from the link below and then move the downloaded zip file to your desktop

http://downloads.oneplus.net/oneplus-3/oneplus_3_oxygenos_3.5.2_community_build/

Step 2: Reboot your phone into recovery by turning off your phone and then holding the volume down and power button together for about 5 seconds.

Step 3: Now you are on recovery screen.Select the language as "English" and then choose "Install from USB" and then select "OK"

Now you are in the recovery screen showing "You are in Sileload mode"  

Step 4: Now connect your device to PC.Open command prompt in your PC and then run the following command

                                 "adb sideload"

 and then drag and drop the zip file from desktop next to the command.

Press Enter key 

 Be patient until the phone is updated and then select "reboot"