EDF5 .SHKT files can be opened in Havok Content Tools by changing the file format to .HKX.

The installer of Havok Content Tools I tested with is called "HavokContentTools_2014-1-0_20140830_64Bit_PcXs.exe", other tools that can open Havok files from other games like Skyrim, Fallout 4 and Breath of the Wild can sometimes open these renamed .HKX files too.

There is a google drive with various versions of Havok Content Tools here.

GUIDE:

In your extracted EDF files, find the .SHKT file you would like to modify and change the .SHKT part of the filename to .HKX.

Open the application "Havok Standalone Filter Manager". It will immediately ask you which file to open, find your .HKX file and press "Load", it will ask you for another file with the same looking window, just press "Done". On the next small window that pops up, just press "OK" and the main tool will finally open.

In the tool, select the "Write to Platform" filter, then "Add" and set the format to "XML". Press "Run Configuration" and a new .HKT file will be made alongside the original .HKX. This file is a readable and editable XML, open it in Notepad++ or whatever editor you like to use and make the changes you want!

To re-import the file to EDF5, open the .HKT in the same way you opened the original .HKX but select "Binary" instead of "XML". The .HKT that you just modified will be overwritten with a game-ready file.

The final step is to rename the generated .HKT to same name as the original file you wanted to modify, then placing it in your mods folder in the correct subfolder. When you launch the game, the .SHKT will be loaded and the changes you made should show up ingame! If you modify a setting that havok does not like, it will show an error during the previous step.

SHKT format structure

The structure of the SHKT format, which is not necessary if you can find a havoc tool for EDF5,6.

• The first 4 bytes indicate the end-of-file position.
• The bottom row has blocks beginning with “TPAD”.

TPAD table

Offset	Size	Description
0x00	4	"TPAD" header
0x04	4	Offset to TPAD table end
0x08	4	Unknown
0x0C	4	Unknown
0x10	4	Unknown
0x14-	-	TPAD data

TPAD data : 0x0C bytes

Offset	Size	Description
0x00	1	Data type
0x01	1	00
0x02	1	00
0x03	1	10 or 20 (Data start position? Header size?)
0x04	4	Data address(absolute)
0x08	4	Data count (Depending on the data type, it may be the number of blocks or the number of characters.)

Data type (this is not all) : EDF5

Value	Data size	Description
0x95	0x04 * 12	Body collision setting
0x14	0x04 * 4	Bullet collision setting
0x0D	0x01	string data

Data type (this is not all) : EDF6

Value	Data size	Description
0x76	0x04 * 3	Body collision setting
0x3E	0x04 * 4	Bullet collision setting
0x0C	0x01	string data