A while back when the OTA update came out for Lollipop 5.0, the tablet became exceedingly slow, practically unusable. So, I followed the instructions in https://developers.google.com/android/nexus/images and reinstalled the 4.4.4 ROM. The system continued to offer the upgrade but I ignored it. Today, I tried to install it. It is offering 5.0.2. It says that it has already been downloaded (~300Mb) but when I tap on Restart and Install, it says "rebooting in x seconds" until it says "rebooting now" but never does. The it says "downloaded and verified" again and the button changes back to "Restart and install" from "cancel install"
I tried doing this operation in safe mode but to no avail.
A few weeks ago, I cleared the cache partition a couple of times, if this has any importance.
Is there a way to redownload Lollipop OTA without sideloading?