REPLACE SYMBOLS WITH SCRIPT

I am looking for a script to load an external symbol library. The library should be opened in an open document that has already a symbol library with symbols placed on the workspace. If the symbol from the loaded library has the same name than the existing symbol in the open document, the symbol should be replaced and the placed item, linked to the symbol should also be changed on the workspace.

I found already this script that opens an external library and put the symbols items into the open symbol library, but is it possible to replace the symbols with the same name and also replace the linked symbol placed on the workspace. This script should save me a lot of time !  I’m not an expert in scripting so any help or tips should be welcome.

Existing script to load external library (source: Stackoverflow): How to load a symbol library in Illustrator using javascript? - Stack Overflow