PS: AFAIK, it is consider good forum manners to post your question in a single forum and not cross/double post at the same time. If you have not had a redponse in days, you may want post again in a different forum and probably rephrase your question.
Download the zip file from his site and it has all of the DLLs required as well as sample code.
In essence you import his modReportToPDF module into your app, copy 2 DLLs into your %systemroot%\system32 folder and call his function as follows:
MergePDFDocuments(varMaster, varChild)
The varChild PDF will be merged into the varMaster PDF when the routine is over.
To create the PDF in the first instance can be done with Stephen's utils, but I personally prefer the following command:
DoCmd.OutputTo acOutputReport, varRpt, acFormatPDF, varChild, False
This works only because of the fact that I am using Access 2007 with the Save As PDF/XPS util from MS installed.