Termination of a probate guardianship by way of a 388 modification petition was harmless error. Inez, the maternal great aunt and former guardian of the minor, appealed the juvenile court order terminating the probate guardianship because the court failed to follow the statutory procedure for termination, in that the application to terminate the guardianship was raised by section 388 petition rather than by a motion pursuant to section 728. Further, the father was not given notice of the guardianship termination proceeding. Inez contended that the errors were jurisdictional and subject to a per se reversal. The appellate court held that although the Department did not follow the statutory procedure for notice and termination, the errors were not jurisdictional and did not compel reversal. The requirement of a motion rather than a petition for modification is not fundamental to the structure of the dependency scheme, but is a mere procedural requirement. Inez did not object to the procedure utilized by the Department, and there was no prejudice by use of the improper procedure since the petition for modification subjected the Department to a greater burden of proof than a motion would have.