How can you save the director in radio tower in Pokemon HeartGold?

You must defeat the Team Rocket Grunts and Executives at the Radio Tower, and Petrel will give you a key to the locked door in the Goldenrod Tunnel, then navigate through the Tunnel, defeating Grunts along the way, until you finally find the Director at the bottom of the tunnel. He will thank you for finding him and ask you to save the Radio Tower. When you do, he will give you the Rainbow Wing in HeartGold, or the Silver Feather in SoulSilver. I hoped this helped you!