Hi Pavel,
LP_XMLConverter does not have a function for that.
I suggest to change the libparts’ Main ID during step 3. It is in the first lines of the xml, as MainGUID="0884EDB2-4B1B-4247-874E-36DB88381443"
You can create new guids with many editors, or you can use online tools, for example:
https://www.guidgenerator.com
Gergely Fehér
Team Leader, Library Team
GRAPHISOFT SE