An installation with Eclipse IDE requires the installation of the following:
Java Runtime Environment 5.0 or higher.
Eclipse (Eclipse IDE for Java Developers).
Android SDK (Google).
Eclipse Plug-in (Android Development Tools - ADT).
Then describe the process to follow to install the above software. If you already have Eclipse installed on your computer you can complete the installation by adding Android SDK and Eclipse Plug-in. Keep your current settings and just be adding new features.