[Chiuso] Re-assign an existing translation to a different target language

Background of the issue:
I have a website under development where I am working on a translation. The client initially wanted the site in Serbian but requested the Bosnian flag to be used. I set Bosnian as a secondary language and started translating. However, the client now wants everything switched to Serbian, with the Serbian flag and the 'rs' code instead of 'bs'.

I have a website where I am currently working on a translation. The client wanted the site to be in the Serbian language, but instead of the Serbian flag, the Bosnian flag should stand. Since Bosnian and Serbian are almost the same languages ​​as writing, I did as he wanted, set Bosnian as a secondary language and started translating.
However, when the client saw that the link contains the "bs" code instead of "sr" when the country flag is clicked, he gave up and now asks me to switch everything to the Serbian language, to set the flag of Serbia and that it now contains the "rs" code.
Is there an easier way to solve this, to just replace the images of the countries and the code, or do I have to translate everything from the beginning in Serbian?

Symptoms:
The client is unhappy with the 'bs' code in the URL and wants it changed to 'rs' without redoing the translations.

Questions:
Is there an easier way to replace the images of the countries and the code without translating everything from the beginning in Serbian?