Firstly, check that your mindset is not clouded by bias and assumptions based on your prior experience with the person with whom you are about to have a conversation. Approach the coming conversation as a new and fresh experience.
Prepare well by having evidence of the issues you are hoping to discuss at hand. BUT do not share these unless the other person’s blindspot convinces you to share the evidence with them.
Be compassionate with all your focus on re-setting the other person by sharing your perspective and highlighting the impact they are having on you and the team.