>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.
>
I applied them manually, but later I found an option to Merge two documents (ouch, forgot how I did it).

Also my colleague suggested to put user's info in Tools\Options\User Information. This would allow us to see who made the change.