1. Open the ITD file in SDLX Edit. Unfortunately you have to do this file by file.
2. Export the ITD file using File > Export to TRADOStag TTX format. The resulting file has the extension *.TTX.
3. Create a project in DVX.
4. Import the TTX file into DVX using the Wizard or Project Explorer.
5. Translate the file in DVX.
6. Export the file from DVX using Encoding option Unicode (not Unicode UTF-8!).
7. Make sure the original ITD file and the exported TTX file are in the same folder. Then import your translation into SDLX using the SDLX option File> Trados > Harvest exported TRADOStag TTX translation. The ITD file has been updated with your translation, but you still have to update the segment statuses in SDLX (that is, make sure that the grey and green segments [and also the golden segments if you need to deal with the full matches as well) are blue [= confirmed]).
8. Deactivate the SDLX options Auto-Propagate and Auto-Match BEFORE you start confirming the segments in SDLX.
9. Check the ITD files and confirm every translation (Edit > Confirm/unconfirm > Confirm all three options (100%, fuzzies, untranslated) subsequently. Most of the codes should be preserved and put in the right location.
<Addition below by Rob_Laumen>
N.B. Regarding step 1, 2 and 7: the new SDLX 2006 version has an Exchange module which is available from the main GUI ("switchboard") and allows you to quickly convert SDLX files to TTX files and 'harvest' TTX files into SDLX files, so you no longer have to manually convert files one after the other.
N.B. 2 DVX will NOT import ITD files that have Format Painting issues -- these need to be solved first. Refer to the online Help of the SDLX program for information on how to do this.)
</Rob_Laumen>