The easiest way to install is to use the Install/Update Feature of Eclipse.
How to use the Install/Update Feature:
Configure Proxy: Go to Preferences > Install/Update
Check Enable HTTP Proxy Connection and fill in host and port.
Go to Help > Software Updates > Find and Install ... >
Search for new features to install in the main menu.
Fill in a New Remote Site with any name (e.g. "ServerEclipse update site")
and the Eclipse Update URL: http://servereclipse.sourceforge.net/update