Serial Loops has a menu for modifying the core user interface text. The UI text consists of the text that displays on the main menu, CONFIG, file select, and save data management screens, ticker-tape tooltips, and popup prompts.
The UI Text editor can be accessed through the "Edit UI Text..." option in the Tools menu.
Clicking the option will open the UI text editor. This presents a panel detailing every UI text item in the game, each with a label identifying what that string represents. Modify the text in the boxes to your liking, and choose "Save" to apply your changes and update the menu text.