Okay. Start out going to the right and go into the door surrounded by blocks that form an "H." Next, go right again until you pass four doors and go into the fifth one that is on three blocks. Head right, hit the P-Switch, and go into the first door you see. While the P-Switch is still active, keep heading right and go into the last door you see, which is on a lone block (the door won't appear if the P-Switch's effect wears off). Finally, all you'll have to do is hold Down to avoid getting hit by the spikes, if you have a power-up, and fight Boom Boom.
