You'll find the translation .csv files and .txt files in the \steamapps\common\The Spy Who Shrunk Me\The Spy Who Shrunk Me_Data\StreamingAssets\Translations\English directory.

Start off by copying the default English translation to its own folder.

Name your folder to the name of the language (eg. "FinnishLanguage").

Simply replace the (usually third in line) key values to your local language. You'll need Excel, Notepad++ or similar text editing software to do this.

Make sure your language files are in their own folder with the .csv and .txt file ends intact! Otherwise the game might not load them properly.

You can download the tool from this link: https://catland.studio/tools/SpyWhoShrunkMeWorkshopUploader.zip

The tool is used to submit your ready-made translation to the Steam Workshop.

You must first click "Create new item" and upload the information required, then move your translation files to the folder created inside the tool's installation folder /WorkshopContent/.

Your currently logged in Steam account will be the one uploading the file.

After this, submit your translation. If all goes well, you should see your entry in the Steam Workshop under your submitted files. Simply put the item status to "Public" to make it available for everyone.

To use your translation, simply subscribe to the translation item on the Steam Workshop, go to the Options Menu and toggle the language under Display -> Language.

If you need to update your translation, use the Workshop Uploader tool again and re-submit, this should automatically update the files.