You can use the "compare documents" feature - comparing to your original document - to see exactly what changes each one did.
However, I don't know of an automatic way to apply all the changes.
>Hi everybody,
>
>I created a draft document to get input from my colleagues. Two of them already replied and sent a document with the comments as attachment. How can I merge these changes (I saved them as two different documents) and how exactly should I share the document?
>
>I can put it to VSS, I guess.
>
>Would you please tell me?
>
>Thanks in advance.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)