Here's some of the tools I use to break things for fun. And they're all free!
Blender - https://www.blender.org/download/
GIMP - https://www.gimp.org/downloads/
paint.net - https://www.getpaint.net/download.html
LegendaryExplorer - https://github.com/ME3Tweaks/LegendaryExplorer/releases
Notepad++ - https://notepad-plus-plus.org/downloads/
UAssetGUI - https://github.com/atenfyr/UAssetGUI/releases
Unreal Engine - https://www.unrealengine.com/en-US/download