This guide shows how to remove the back case from the Nexus 4, giving access to the internal features of the phone. This will take a couple of minutes.
Gently open the back case by prying along the edge of the cover, starting at a corner of the phone and circling around the phone using a plastic opening tool.
The opening process may take a few minutes. The plastic will make a light snapping noise as the back cover separates from the rest of the phone.