Before you do anything:

• Make a backup of your own save files if needed
  
• Turn off Steam Cloud for The Quarry if necessary
  
• Bear in mind spoilers (obviously..)

Save Files location - C:\Users\YOUR_USERNAME\AppData\Local\TheQuarry\Saved

Jacob told Emma the truth

• Download the save file[mega.nz]
  
• Launch the game and load the save file
  
• During the cutscene choose the following dialouges: Honest, Remorseful, Apologetic

Killed everyone

• Download the save file[mega.nz]
  
• Launch the game and load the save file
  
• During the cutscene just fail QTE events and kill Kaitlyn - everyone should be dead now
  
• Continue the game till the epilogue

Ryan survived alone

• Download the save file[mega.nz]
  
• Launch the game and load the save file
  
• During the cutscene just fail QTE events and kill Kaitlyn - everyone except Ryan should be dead now
  
• Continue the game till the epilogue

Kaitlyn survived the night alone

• Download the save file[mega.nz]
  
• Launch the game and load the save file
  
• During the cutscene save Kaitlyn by throwing the toy into the freezer and locking Caleb there
  
• Continue the game till the epilogue

Please note that I'm not 100% sure if the achievements will pop up for you with this save files as I don't really have the possibilty to test it by myself (already own the achievements) - thus, I will appreciate your feedback on whether it works for you.

I also hope that I did not mess up any of the save files during the process of creating this guide but if so please let me know as well and I will try to fix it as soon as possible.

If you have any questions or feedback, feel free to leave a comment!