Software updates keep downloading

First off let me say I am new to the android scene I just switched over from iPhone last week after using iOS for the last 7 years so I'm still learning, I've already rooted my phone but im having a small issue.

I've disabled the software updates on my Nexus 6p through Google services framework but I still keep getting notification that its downloaded and needs installing, is there anyway to keep it from doing this?

I've tried running the install to remove the notification but a few hours later it comes back.

Thanks Kindly