1. Rename your "old" ResXXX.dll to ResXXX.<build>.dll
2. Copy the latest ResEng.dll to ResXXX.dll
3. Do the same steps as you would translate it the first time.
    See Documents

4. Export the string and dialog resources from the "old" ResXXX.<build>.dll
    and import them into the new ResXXX.dll

5. Update the resources
    For major resource changes a correct update is very likely only possible
    if you're using a localization tool with update/comparsion features
    (eg. Alchemy Catalyst).
    If you don't own such a tool it's safer to start the localization from scratch.
    For minor changes all tools should do their work.

IMPORTANT
- Do not import everything from the old dll because the ResEng.dll contains
  updated icons, bitmaps and binary resources.