how to add a linked part / assembly to an EXISTING BOM??

Hey Guys,

I have a drawing in which I have an existing BOM that already contains sorted data etc. that I want to keep. without starting from scratch...

Now I have a new Assembly that I simply want to add to that existing BOM - this new assembly I would like to liink to the old BOM...  and jwith that the parts as well... I am assuming that I will repeat for both the assembly as well as the parts?

All help greatly appreciated!!

Cheers.

SolidworksDrawings And Detailing