Hi,
The Correo_Electronico node is not the root node of the returned document, it is a child of the root, so to address it you do not need the leading slash in your XPath expression. Try this instead:
update replace input()/Peticiones[Correo_Electronico="mirizarry@gmail.com"]/status with <status>no</status>
#API-Management#Tamino#webMethods