This is what in the first "installation txt" file
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4images Language-Pack Installation
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Entpacken Sie das .zip und laden sie den Ordner ins "lang"
Verzeichnis auch Ihrem Server. 4images erkennt das neue
Language-Pack automatisch. Sie können die neue Sprache dann
über Ihr Control Panel auswählen.
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Decompress the .zip archive and FTP the folder to the
"lang" directory on your server. 4images will detect the
new Language-Pack automatically. You can choose the new
language it over your Control Panel.
This is what in the second Installation txt
Replace the german image files with the files in this folder if you need.
templates/default/images/
There's no intallation instructions there for 4images. I downloaded the "english" version of 4image.