Step 2: Make Sure that your device’s bootloader is unlocked and you have successfully installed TWRP Recovery. If not then follow the below link to do so.
Step 3: Now Boot into TWRP Recovery mode and do a full factory reset and data and cache wipe.
Step 4: Next Go to Install in Recovery mode and flash the downloaded ROM zip file followed by GApps file.
Step 5: That’s all After successful installation reboot your device.