Won't that wipe everything?
Guys. Dont' flash. Do ADB Sideload. You won't use the factory images (.tgz) but rather the actual OTA zip files.
zips from here: http://www.androidpolice.com/2014/11/17/flash-all-the-things-lollipop-ota-update-zip-file-roundup/
instructions here: http://www.androidpolice.com/2012/1...e-nexus-7-now-manual-download-link-available/
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