XDA Member Sachi315 was able to get the first Developer Preview of Android O rooted on their Pixel phone, and now we see XDA Senior Member has put together a step by step guide to help everyone do the same. The method involves installing an Android 7.1.2 ROM onto one slot of the device and installing the Android O Developer Preview onto the other slot (remember that the Google Pixel phones have two sets of partitions because of its seamless update setup), and flashing Chainfire’s Extra Delay SuperSU.