Many customers translate a language code (e.g. generic Spanish) and then decide later on to change the language code (e.g. to the Spanish Spain language code).
Here is step by step how to do that:
#1: Add the desired languages to your project via the “Edit languages” button that is available on your project’s languages page.
#2: Download the generic Spanish translation file.
#3:Re-upload them as translation files under the new language (Spanish Spain)
After proceeding with the above steps, feel free to remove the languages that you are not interested in anymore.
If you would like to change the source language, you will have to create a new project with the new source language, add the target languages, download the files from the old file and upload them under the new project, under the referent language. You can then archive or delete the old project.