Well..., I think I have found the answer to my question.
First of all, the
video tutorial nr.27
explains "CB Language Plugins Initial Concepts and Transifex".
This forms a nice base for the next
tutorial nr.36
, which deals specifically with "CB Language Override plugin and how to use it".
Once you have gone through the recommended actions in the second video, (installing the experimental language-override-plugin and copying the needed files...) you can start inserting other text translations.
Now the only remaining item is, to find the correct string to translate, and put it in these newly created files.
Also, the search for the experimental CB language-override-plugin took me quite some time. There was a reply somewhere mentioning it would be "in the first post". As there was no further explanation, I had to zift through many posts in the forum, and finally found some hidden link to this file, in a completely different reply.
Unfortunately I would not be able to repeat the location here...
Hope this helps someone,
Burnardo