Pocket Rocket

It seems overkill, but Jonnie plans to use the rocket launcher to wipe out some suspicious people who have been driving past his bar recently.

Excessive Firepower

Make your way to the docks where you'll find the weapon waiting for you. Once you pick it up, you'll be attacked by three guys on foot.

Upon killing the enemies by other means, two or three more will come at you, alongside a vehicle. Keep shooting them until they're all dead, and/or blown up.

When they're all wasted, head back to the bar with the Rocket Launcher.

Mission Passed!