Unren's 9 just does all the various things Unren can do. The post in question was presumably referring to unpacking the RPA files, the 1 option, which includes extracting all the pictures in the game. (They'll be in a sub-folder, often game\images, though I can't remember the pathing of SoC files for sure.) Using Unren to enable console/dev menu (3, though 9 obviously does it too) does enable a thing in Rowan's room to view scenes, but that's hard to navigate if you don't know what scenes are called and also doesn't contain some scenes.
The only real way to use the Scene Replay is to change the code, as the Scene Replay feature has been broken for a long while. Luckily there's a
great mod that does that.