This approach preserves the original game and simplifies uninstallation.
Launch the game. If the "paperwork" (map file) is correct, you can cycle through kits in the selection screen using the keys to switch between "GDB" and "Internal" kits. Team ID list for a specific league to help populate your map file? How to Import Kits to PES 2013 [TUTORIAL] How to Import Kits to PES 2013 [TUTORIAL]
The GDB was a game-changer; it allowed for an "infinite" number of kit combinations, enabling modders to add third, fourth, and classic kits for teams that previously only had two. The Challenges of Modding
The numbers were team and kit IDs. 128 was Man United’s internal ID. 109 was the generic “away” slot. He then copied the new kit PNG files—home red, away white, third black, and a stunning blue goalkeeper kit—into the respective folders.