Fairly straightforward. You want to be doing this on level 4-1. Get rid of all but one of your shots by firing them at low power away from any buildings. Then, with your last Basic Shot, fire it at the corner of the large building at the back. You want to be aiming for around the same spot as shown in this video (which I'm not taking credit for, thanks to leadexample for that). Except obviously you should aim to hit the bank just before the collision. Easy.