How to unlock bootloader, Install TWRP, Root and Install Custom Rom on Oneplus 3

Rooting the OnePlus 3 is an easy process, before you do it you need to do perform a few other important steps: install ADB and fastboot, creating a backup, flash custom recovery, and unlock the bootloader, which opens doorway to the internal memory of the device, allowing you to flash images to the phone's main partition.

Thankfully, there is an all-in-one toolkit available to get all the above functions done by just one click. But if you are looking for manual methods, consider following the instructions shared by recognised XDA contributor Naman Bhalla.

How to install ADB and fastboot
•Download ADB for Windows
•Run .exe file you just downloaded
•Press Y when the installer asks for 'Now  continue with the Driver Installation'

How to unlock bootloader
•Turn the OnePlus 3 off.                                   •Boot it into fastboot mode by holding Volume  Up and Power buttons together. You should  see fastboot text being displayed on the  screen.                                 •Connect your phone to the PC. Open a  command prompt window on your PC. For this  hold Shift + right click >> Click Open  command  window here from the drop down  menu. In the  command window execute the  following  code:fastboot devices.           

•This command will help to list the connected devices.                                               •Click the following command to unlock  bootloader: fastboot oem unlock. It is  important to note this process will wipe out all  data of the phone, therefore create a backup  before you go ahead with this process.

Now reboot the phone by typing in:fastboot reboot

After you have successfully unlocked the bootloader, perform the following settings on your OnePlus 3.

Enable USB debugging: Go to Settings>> About phone then tap the Build Number seven times, which will enable Developer Options. Now again go to the Settings>> Developer options then click the box for Enable USB debugging.

Enable OEM unlock: Head over to Settings>> Develop options then enable OEM unlocking option.

Advanced reboot: From Settings>> go to Develop options then enable Advanced Reboot.

How to flash TWRP recovery

• Download TWRP recovery file.
• Switch the phone off and place it into recovery mode.
• Rename the recovery file torecovery.img
• Open a command prompt on your PC and type in the following command:fastboot flash recovery recovery.img
• After the installation is complete, disconnect the phone from the PC and manually boot the phone into recovery by holding Power and Volume Down buttons together.
• While you are in TWRP recovery, select Reboot from the menu and then select System. The phone will now boot into System.

How to create nandroid backup

• Boot OnePlus 3 into recovery mode.
• Navigate to backup menu and select the listed partitions.
• Swipe to create the back-up. This step will take some time.
• When it's finished, reboot the phone.

How to root with SuperSU

• Download SuperSU root file.
• Connect the phone to the PC then move the SuperSu file to the storage of the phone.
• Disconnect the phone and turn it off.
• Boot it into recovery mode.
• From the recovery mode menu, select Install>> then select SuperSU file.
• Do a swipe to confirm the installation the reboot it.

How to install custom ROM

• Download any custom ROM you want, then copy it to the internal storage of the phone.
• Switch off the phone and boot into recovery mode.
• In the recovery menu select Wipe>> Advanced Wipe>> select Dalvik + System + Data + Cache then swipe to perform wipe.
• When the wipe is complete, return to the recovery menu, select Install then head over to the location where you have saved the ROM, select it and swipe to confirm the installation.
• Use the same process to install Gapps and reboot the phone. Note that the first boot will take some time.

How to create EFS backup

• Launch Terminal Emulator on phone.
• A command line prompt will now be displayed, wherein you can enter text commands. Enable the root access by using the following line: su
• Then enter both the following commands:

dd if=/dev/block/sdf1 of=/sdcard/modemst1.bin bs=512

dd if=/dev/block/sdf2 of=/sdcard/modemst2.bin bs=512

Doing so will place two files in phone's internal storage. Copy the commands to your PC or other clouds to make a back-up.

If you have any doubts or hit problems, visit the development thread at the XDA forum.