Stopping Team Rocket
Fly to Goldenrod City after you have defeated the Mahogany City Gym Leader to confront Team Rocket. Locate and battle a Team Rocket Grunt in the underground area of Goldenrod City to obtain a Team Rocket uniform. Walk to the Radio Tower in Goldenrod City and battle your way to the top to confront the Team Rocket leader. Defeat him with your highest level Pokemon to obtain the Silver Wing.
Blackthorn City Gym
To obtain the Tidal Bell from the Kimono Girls, you must defeat the final gym leader at the Blackthorn City Gym. Travel to Blackthorn City by heading north on Route 45. Clair, the gym leader, uses high level Dragon Type Pokemon like Gyarados and Kingdra. After defeating her Pokemon she will make you go to the Dragon's Den, an area located under the city. Answer the master's questions in the Dragon's Den to receive HM07 Waterfall, which is needed to reach Lugia.
Facing the Kimono Girls
After obtaining your final gym badge in Blackthorn City you will receive a call from Professor Elm. Fly to New Bark Town to receive the Master Ball from Professor Elm. Fly to Ecruteak City and head to the theater to confront the Kimono Girls once you have the Master Ball. Bring your strongest Pokemon as you must battle each of the five Kimono Girls in a row without saving. After the battle, they will give you the Tidal Bell.
Battling Lugia
Travel to the Whirl Islands to meet the Kimono Girls. Use the HM07 Waterfall ability to travel to the underwater caves and make your way to the back where the Kimono Girls are waiting by a waterfall. After they summon Lugia you will need to successfully weaken the Pokemon using your strongest attacks and capture it in a Pokeball. A Heavy Ball or Speed Ball is recommended. If you fail to capture it, Lugia will reappear after defeating the Elite Four.