Modding information of Torment: Tides of Numenera is listed here.
Change Portrait
1. You need an asset viewer, like Unity Asset Bundle Extractor tool (UABE). (which you can find online)
2. Open resources.assets in WIN/TidesOfNumenera_Data folder inside your Steam TTON game folder
3. Find textures Portrait-LCO_Male and Portrait-LCO_Male and extract them as tga using the Plugins button on the right
4. Edit the textures in your preferred graphic editor
5. Import the new textures to replace the old one using the "edit" Plugin in UABE
6. Save the changes resources.assets (this will create a new file sharedassets4.assets)
7. Replace the original sharedassets4.assets file (located in the same folder as resources.assets) with your new sharedassets4.assets
8. Start a new Game with your new portrait
