Internalizing an external part within an assembly

I have recently crossed over from AutoDesk Mechanical Desktopto SW07. One thing I am struggling with in SW is how to take anexternal part and internalize it to an assembly. When making amodification to an existing machine I often have to re-draw part ofthe existing machine as a reference for the new design. Currently Ihave a mountain of files with no purpose other than referencegeometry. We have a document management system so I am not realthrilled about have to catalog reference files. Anysuggestions?SolidworksAssemblies