Tools You Might Need.

Notepad++: A simple but good enough Text editor
Sublime Text: A more advanced text editor, very useful for coding, has paid and free option
WinMerge: Tool for comparing and merging files
Everything: A simple but pretty good search engine that gets the job done
Agent Ransack: an advanced search engine for power users

Paint.net: Tool with DDS import and export functionality and, in general, a pretty good photo editor
Renderdoc: Graphics debugger very useful for figuring out what dds format your photo is in
Dying Light 1 Developer Tools Rpack repacker For .rpack Repacking, which will allow texture editing and a lot more you need its was a hidden tool for years until 12Brandon34 discovered it

Daemon's RP6L Unpacker For .RPACK archives (textures and meshes) is very useful since it can convert Dying Light meshes to an openable format in Blender with the use of the XNALara plugin
XNALara: Compatible with Blender 3.6 and earlier versions for .ASCII meshes
Dying Light 1 Developer Tools: Very useful in general to do a lot of base game editing and custom map editing. You need to own the game to use it; hopefully that will change in the future

Bin Editor Tool a simple tool that would allow us to edit the bins file, which contains the text Dying Light uses. So, in summary, we can edit text with this tool