Invite a teammate, change roles, remove someone, Help

Open Settings (bottom of the left sidebar) › Team › invite, enter their email and choose Send invitation. Owners and admins can invite; admins invite as members only. Owners change a member's role (Member or Admin), remove people and transfer ownership on the same page; admins can remove members. Pending invitations can be revoked there. Invite people (⌘K) goes straight there.