Looping through properties of an object and changing the value of the properties

I want to loop through the properties of an object and replace a value in a string. The properties are all string types and I want to replace any < characters with &lt;

I found some code at https://www.pluralsight.com/guides/microsoft-net/property-copying-between-two-objects-using-reflection that looks helpful, but I cannot figure out how to change the value of a property in the parent object before it's assigned to the child object.

The line in question is childProperty.SetValue(child, parentProperty.GetValue(parent)); I want to be able to to the replacement above to parentProperty.GetValue(parent).