I'm looking for the same thing, but the macro in the post about lynkoa is just to open the PDF that's in the design log of the part. It doesn't open all the PDFs in an assembly.
@maximus : It's normal that the macro present in the post on lynkoa only opens the PDF which is in the design log of the part since it only lists the files attached to the active document in Solidworks (Set swModel = swApp.ActiveDoc). To do what you want, you need to add a loop that lists all the components of the assembly to get the IModelDoc2 objects of these components (see the GetModelDoc2 method in the APIs) ...