If you have a team member who is causing problems, you can use assertiveness to manage them in a constructive and respectful way. To do so, begin by identifying the problem and its impact in a specific and factual manner. Then, prepare your message, focusing on what you want to say and how you want to say it. Make sure to use "I" statements to express your feelings and needs, rather than blaming or accusing the team member. Choose an appropriate time and place to talk to the team member privately and calmly, without interruptions or distractions. When delivering your message, be firm but polite. Listen actively and empathetically to their side of the story, acknowledging their feelings and perspectives. Work together to find a mutually acceptable solution to the problem, summarizing the main points and confirming the agreement. Finally, follow up with the team member regularly to monitor their progress and provide feedback, support, or recognition as needed.