Download a complete kit pack (e.g., "PES 2017 Premier League Kit Pack"). Inside the pack, you will find folders named after teams (e.g., Liverpool , Arsenal ). Copy these folders into: kitserver17\content\kit-server\Kits\
Kitserver is a module-based extension—often used alongside the Sider tool—that manages player and goalkeeper uniforms outside of the game’s standard internal files. Instead of overwriting limited slots, it uses an external database (the GDB) to assign an unlimited number of kits to any club or national team. kitserver pes 2017