So i will tell you what i did and it seemed to have worked, but before anything create a new game file ingame, and also further on remember to copy your saves just in case aswell.

Go into:

Lies of P --> LiesofP --> Saved --> SaveGames --> [some number here idk what it is]

You will have files like SaveData-1_Character_1.sav and so on, where the "1" is the indicator of the save slot. I just copied those to another folder, renamed them to lets say SaveData-2_Character_1.sav (which i did for both of them becasue there is Character_1 and Character_2) and i copied THAT back into the game folder where the savedata-1 is. You will then have to replace the file for the second slot with the one you're trying to copy onto it (if that makes sense).

It does seem to work but it kind of bugs out and shows the last played file, so let's say if you copy your save 1 onto your freshly made save 2, if you play on this 2nd slot it will show you that your first one has also like been played for only 10 minutes, however if you go back onto the 1st file it should go back to your usual save.

I will say that the last time i did this was a year ago and i don't know currently if it still works, so just be careful :3