Other Major Tools

These are other tools that aren't specific to any one form of editing, rather you're just gonna need them for everything.

CRIFileSystem
The data of PES is stored in bunches, specifically known as .cpk files. The CRIFileSystem can read, assemble and disassemble .cpk files, essentially opening up the inner workings of PES 2017 for you to see.

Extracting the files of a .cpk makes them retain their folder structure, which means you can see where the game stores its resources and the locations that PES expects to find them when it runs. The intricacies of using CRI to both look at PES and make DLC for it is explained fully in Creating DLC.

PES Decrypter 2013
If you, out of curiosity downloaded CRI and started poking through PES, you may have noticed some files open as gibberish, or are straight up unreadable. These files have been compressed with zlib, a lossless data compression library, modified slightly for use by PES.

Zlib is applied to numerous different filetypes, including .xml, .mtl, .dds, and .bin. If you want to check if a file has been compressed with zlib, open it in notepad. If you see "WESYS" at the front of it, that means it's been compressed by zlib for PES (This is the modification mentioned before. It's almost completely insignificant). Files do not need to be zlibbed to be read by PES, but it does cut down on space when they are zlibbed.

The Decrypter works on a click-and-drag system, simply drag whatever file you want to zlib or unzlib and the tool does the work. The main tool only works on one file at a time, though there is a second tool that can alter multiple files at once. The PES Edit-Crypter included with the Decrypter has the capability of handling multiple files at once, but does not keep their filenames in order when the process is complete. Which one you use is up to you, it just depends on whether you prefer individually clicking and dragging, or going back renaming everything once you're done with the tool.

DPFileList Generator
Baris' DPFileList Generator is the wrap up tool you'll need once you're done packing up your DLC. Just grab it for now and it'll be explained in Creating DLC.

Downloads

 * CRIFileSystem: https://drive.google.com/drive/folders/1zEfn_1nWDXyk5MBgr__9XxT7ku2ijGUI?usp=sharing
 * PES Decrypter 2013: https://drive.google.com/drive/folders/14g_3t3vknUQ57XP27-it6melL1FfWdTp?usp=sharing
 * DPFileList Generator: https://drive.google.com/drive/folders/14J4CX5RGdwu_49PnQTHwhcwmUAXNLE0p?usp=sharing