Download Carbon Copy Cloner from here and save it to your desktop.
Double click the downloaded dmg (example ccc-3.2.1.dmg) file to mount it.
Drag and drop the Carbon Copy Cloner icon onto the applications shortcut.
Double click Carbon Copy Cloner from your Applications folder to launch it.
Once the application has opened select the source disk to copy from using the dropdown on the left.
Next select the target disk to copy to using the dropdown on the right
Click the Clone button at the bottom right of the screen to begin.
You may be asked for your administrator user name and password. Enter these then click the OK button to continue.
Carbon Copy Cloner will now make an exact duplicate of your source drive. This may take some time.
Once complete Carbon Copy Cloner will inform you that it has finished successfully. Click the OK button.