The Nexus adb instructions go something like this:
• Settings > About phone, tap "Build Number" 7ish times until "Congrats! You're a developer!" is displayed
• Settings > Developer options, tick "USB debuggin" option
• Connect phone to computer via USB, and execute an adb command
• Receive prompt to permit the connection; do so, and then execute the adb command again. Should work
But, again, not sure if this is at all applicable with Samsung.