Copy the Parts Catalog folders to their respective directories on the local drive or network location: C:\ProgramData\Autodesk\C3D 2023\enu\Pipes Catalog.

Once the catalogs have been copied to the local drive or network location, open Civil 3D and run the command: PARTCATALOGREGEN.

To regen each catalog, enter "P" for Pipes and then "S" for Structures, then exit the command once done.  From here, you should see the newly added catalogs in the Pipe Network via the Parts Lists. 