Installation: copy and replace "Scripts.dir" and "Scripts.img" into the "Scripts" folder located in the game folder.
If you wish, copy the firstperson folder there and edit the configuration script (firstperson.lua), and then run the command script (firstperson.cmd). If you choose not to create a custom configuration, the mod will still work fine with its default settings.
The mod starts automatically when loading a save (game), make a backup copy of the files if you want to return the view from a third person.