I had a pilot at Mecklenburg-Vorpommern already, see the POIs of this changeset. Looks good to me now.
You can find the documention of the mechanical edit here.
In the end, I did not use a script. I wrote it in VBA, and while the script itself was functional, Word and Excel were not, quitting service in the face of the 650,000 lines of xml code. So, instead I used regular expressions in a search and replace, wich took my machine 40 seconds. Yay!