I just did the update myself - I use Triangle Away to work past the detection and do the OTA update, but I had to use the advanced features in the paid version to get it to work. After update you have to re-root it the same way you did the first time. Note that super su might not be installed automatically again, so you might have to uninstall it and reinstall from the playstore after rooting to get it working.
The Triangle Away setting I had to use is "System modified workaround", and the instructions are right below the setting. You enable it, reboot, then disable it and do the update before rebooting. First time I had to try a couple of times, this time I enabled and rebooted, then started the download of the update, then disabled it before installing, and it worked first try.