I could easily be wrong, but, if I had to guess, I suspect the OP meant that if one was given the attached image, how would one get to the image he posted in the 1st post in this thread, and THEN add the distressed look to that.
PS - In other words, I think he is also asking about the very simple process of inverting the image and lifting the blacks to get the first image in this thread, then applying the scratches, dust, etc. to that, ie, a combination of Gedstar and Eggy's comments.
Yes, maybe I was wrong assuming the posted image was already a negative.
If it is your posted image you want to turn into a old type negative film look you should start with inverting the picture:
Go to Image -->adjustments --> Invert (or shortcut ctrl+i)
Desaturate the picture (image -->adjustments -->desaturate) (or shortcut shift+ctrl+U)
Adjust with adjustment layer curves to lift the black color.
Then eventually put the scratch and dust layer on top of it and blend with color dodge.