The requirements of Welfare and Institutions Code section 387 apply where the Agency seeks to remove a child from placement with a relative. Brianna and two of her younger siblings were placed with their maternal grandmother, who was declared the minors’ de facto parent. While in grandmother’s care, the mental and emotional health of all three minors deteriorated. Grandmother admitted she was overwhelmed by the children’s behaviors and that she threatened the children with being placed elsewhere or institutionalized. The Department filed a Welfare and Institutions Code section 387 petition, alleging that grandmother’s home did not meet RFA requirements and that grandmother had failed to obtain mental health treatment and emotionally abused one of the minors by threatening to have her institutionalized. On the date of the hearing, the Department withdrew its section 387 petition, arguing that it was not needed to remove a child from a de facto parent. The juvenile court construed the section 387 petition as a section 385 request to change a prior court order, and found that it was in the best interest of the minors to be removed from grandmother’s care. Grandmother appealed, and the appellate court affirmed the order. Where the Department seeks to change or modify a prior order placing a dependent child with a relative, the juvenile court must proceed under section 387. Section 387 authorizes a juvenile court to change or modify a previous placement order by removing a child from the physical custody of a parent, guardian, relative, or friend and ordering a different placement. If the section 387 petition seeks to remove a child from her parent or guardian, the court must make removal findings under section 361, subdivision (c), but if the petition seeks to remove the child from other caregivers, such as a relative, the court need only find that the relative is no longer able to provide the child a secure and stable environment. The court erred when it applied section 385, however, this error was not prejudicial. The Department followed all the procedural requirements of section 387, including filing a petition, providing grandmother adequate notice, and holding a timely hearing. These procedures satisfied due process, and the juvenile court’s modification order was supported by substantial evidence.