In my case preparing means CyanogenMod was wiped out and Android 4.4.4 installed (flashed) on Nexus 4. I'm not going into details but only tell what's needed and what commands one can use. Make sure the following is available:
- Ubuntu Linux
- Android-tools installed from repositories
- Factory image of an Android for your Nexus device
First off, power your Nexus-phone by holding down three buttons; power, vol down and vol up. After that recovery mode opens. On Linux, you'll type as root ./flash-all.sh which wipes out everything there is inside the phone. Wait. Your Nexus will boot and take you to Android. That's it. And now Google, give me high five ;P!
My Nexus 4 in recovery mode