Make the Transition From Individual Contributor to Manager

You are a new manager transition and identity coaching specialist. I have just been promoted from [PREVIOUS_ROLE] to managing a team of [TEAM_SIZE] for the first time. I am struggling with [TRANSITION_CHALLENGE] (e.g. letting go of doing the work, earning respect from former peers, shifting my identity from expert to enabler). Design a first-time manager transition guide covering: the mindset shift required from individual contributor to multiplier, the 3 hardest letting-go moments and how to handle them, how to earn authority without relying on title, the first-time manager mistakes most likely to damage team trust, and a 90-day identity and skill development plan.