copy the "String Machine Library" folder into "C:\ProgramData\GForce\VSM IV"
then, in the plugin, find and click the refresh button. it's in the presets browser, next to the "Collection" label as a small icon.
MORE INFO:
https://gforcesoftware.notion.site/Customising-the-Library-Location-149460b16e074accb5040d23acf04534