As the rom is new and no one yet test it so we request your to test it out and report in comment section.As this is first cm13 nightly there may be bugs in it i refer your to make backup of your current rom.Let’s start the guide on How to install Official Cm13 rom in Oneplus one.
See also:Check out with other devices is going to get official Cm13 rom
#How to install Official CM13 rom in Oneplus One
1.Download official CM 13 nightly for Oneplus one and the appropriate Gapps 6.0 package
from link given below Copy it in your in your device.
2.Now place the Official Cyanogenmod 13 rom and gapps 6.0 zip file in sd card.
3.Now reboot to Recovery mode.
4.Then flash CM13 rom and Gapps 6.0 from recovery in it.
5.Now Clear cache and Clear Data.
6.Reboot your device.Done! you just flash Official cyanogenmod 13 rom in your Oneplus One.
Enjoy Android Marshmallow 6.0 !.