Just basic how-to and which tools to use for what. I'm not really capable of writing detailed guides for each tool.
How to edit a single DataTable file:
If you want to do larger edits on a file, or multiple files, you can export/convert to JSON using UAssetGUI, and convert them back again using the same.
This is one of the most important bits that a lot of people get wrong. The game looks for UAsset files in specific folders, if it can't find your modded file in that location, it can't load it and instead runs the default.
You can find the Folder-structure several ways, from unpacking the pakchunk and just looking at the folders you have to navigate to find the DataTables, or use either FModel or UAssetGUI to find where they are located.
The basic path is as follows:
BloodstainedRotN\Content\Core\DataTable
This is the folder where the majority of DataTable files are located. Some will be in sub-folders, then you'll need to include those as well.
When making a mod and then packing it with UnrealPak, you should place this inside a folder with the name of your mod, and then drag that entire folder onto UnrealPak's batch-file. Example:
PakContents\BloodstainedRotN\Content\Core\DataTable
Dragging the “Pakcontents” folder ontop of UnrealPak's Batch-file will create a PAK file named “PakContents.pak” in the same location that folder is located.
This tool is used to unpack the main file containing the data:
BloodstainedRotN\Content\Paks\pakchunk0-WindowsNoEditor.pak
The installs/versions I've found has included batch files, that lets you drag the pak-file directly on top, and it starts working. I've had to copy the pak file to the same folder to make it work.
It will take a while, as the pakchunk file is 13gb now. Still the fastest option.
Is a very good tool for browsing and looking through PAK files, including the main pakchunk. It also lets you view DataTables, extract or save as JSON. But won't let you edit anything. Bonus it has a dark mode.
Used to open uasset files, and edit them directly through the GUI, or export/import to json. Do note that the exported json are very messy and need some other program to clean up to be able to use it. Negative: it does NOT have a dark mode.
Lakifume have made a own modified version of this tool, that comes with the “Total Randomization” mod, I recommend downloading that mod and using that version.
Is the only unchanged tool from last version of the game. It's only used for packing the files back into a PAK-file again.
Personally never bothered using the compressions, since DataTables are so small anyway.