Step.1
Find a safe spot from enemies and other damage.
Hint: "The soap bottles on bathub bash is a nice spot."

Step.2
Have a load Bazooka and aim it to the ground 1.5 to 2 meters away from yourself.
Hint: "Dont kill yourself and keep the same distance. Dont move just shoot when reloaded"
Help.. If you get knockback go forward without moving on the mouse / crosshair.

Step.3
Repeat last step 6 times. OFC the thing is bugged..

And there you go!
Happy birthday!