Technically, you don't need a third-party app. KCD has a hidden developer console (activated with the Tilde key ~ on PC). By adding -devmode to your launch options on Steam or Epic, you can access cheat commands.
While there isn't a single "standard" essay written for this tool, the most authoritative documentation and "proper" guide for using a save editor in Kingdom Come: Deliverance (KCD) revolves around Kingdom Save Editor by Xeeynamo. kingdom come deliverance save editor
C:\Users\[YourUsername]\Saved Games\kingdomcome\saves\ Technically, you don't need a third-party app
If you are wondering what to change first, these are the most popular modifications KCD players make to enhance their experience: kingdom come deliverance save editor