[section=Manually] Create a new save with whatever class you want, then exit to main menu before going to 2nd area.

Go to "%LocalAppData%/deathsgambit397/" and go to the folder called deaths_gambit0 / 1 / 2 / 3, the folder you need is whatever slot you saved in minus 1. (i.e. slot 1 is deaths_gambit0)

Open inventory.sav in a text editor that isn't notepad and select all the alphanumeric characters at the start including equals.

Decode that with https://www.base64decode.org/ and you should get something that starts with [player].

Scroll down to [inventory] and find an empty slot close to slot0 and set it to 97:1: for SoR.

Encode your edited save with https://www.base64encode.org/ and paste it back into inventory.sav

[section=DGSaveEditor] I made a tool to make editing inventories easier a long with a list of item ids. (Simply download DGSaveEditor.jar and run it anywhere to edit the 4 main save slots) https://github.com/KayDeeTee/DGSaveEditor