This document provides an overview of the steps to build and install the Android Open Source Project (AOSP) from source. It discusses initializing a build environment, downloading the AOSP source tree and device drivers, building and installing the AOSP build on a Nexus 5 device. The build process involves initializing a repo client, syncing the source code, choosing a target, and running make. The installed AOSP build can then be used to power an unlocked Nexus 5 device.