If I were you, I would make a second file of this drawing before attempting to break down the drawing to reconstitute it in another drawing. If you don't have to explode the drawing you will be better off in my estimation because I doubt that you'll be able to reconstitute all elements as a 3D drawing without spending an inordinate amount of time.
As I stated before, you are better off to Xref or do a Wblock. To do a Wblock, write WBLOCK on the command line, then, you'll be asked to select the drawing, assign a new file name and file it in the directory of your choosing. The drawing will in essence be a copy but with much less data bytes since it was turned into a block drawing.