Paste the Update Site URL into the field named "Work with:" and press Enter. Pressing Enter should cause Eclipse to update list of available plugins and components.
Choose the component listed under Sonar: "Sonar Integration for Eclipse (Required)".
Click Next. Eclipse will then check to see if there are any issues which would prevent a successful installation.
Click Finish to begin the installation process. Eclipse will then download and install the necessary components.
Once the installation process is finished, Eclipse will ask you if you want to restart the IDE. It's strongly recommended that you restart IDE.