How do I change the file referenced in a drawing?

Hey all,

I have a drawing with views in it that were linked to a assembly model.  I wanted to show the assembly without everything else excluding some key components.  I went to the model and saved it as a new copy and did what i wanted but now when I go back to my original drawing Solidworks has updated my drawings with the saved copy of the file. Is there a way to reverse this or do I need to start again?!

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