The installation works as usual with the additional installation of a help file, like this example shows:
GRAIP Lite Pro
Replace the example's toolbox name with that of your own.
For future projects recommend you look into these:
- https://pro.arcgis.com/en/pro-app/arcpy/geoprocessing_and_python/extending-geoprocessing-through-python-modules.htm
- https://github.com/Esri/arcgis-pro-sdk/wiki/ProGuide-content-and-image-resources#embedding-toolboxes (new at 2.4)