from pathlib import Path
p=Path('/opt/struktur/social-media-radar/sources_multi.yaml')
s=p.read_text()
old='''      - channel_id: UCv_TmPtfMuOdETNJADiFNUQ   # Instalaciones Alcolea, verifizierter Technikkanal
        name: "Instalaciones Alcolea – Ventilación"
'''
new='''      - channel_id: UC48ABAQomFZS7FMUEv8P2jg   # S&PVentilation, offizieller Technikkanal
        name: "S&PVentilation – ventilación residencial"
'''
assert old in s
p.write_text(s.replace(old,new,1))