i am new to the android world. i am trying to install Nova Launcher.zip into my system folder. (rooted Gal/Nexus 4.0.2). per the instructions i found that i am supposed to start the phone in recovery mode. i turned the power off then pressed Vol up + vol down + power switch when i select the [recovery mode> Android icon shows up, and briefly later i get the Android icon with a red exclamation mark persisting for a very long time, until eventually the phone reboots normally. not sure what it means, or what to do about it. maybe i am going about this the wrong way to start with. how does one install apps that come in .zip files?