Place kits in \kitserver13\GDB\uni . Organize them by league and then by team folder.
Copy the extracted kitserver13 folder and paste it directly into your main PES 2013 installation folder (usually located at C:\Program Files (x86)\KONAMI\Pro Evolution Soccer 2013 ). Download kitserver13 rar
Right-click the kitserver13.rar file and select "Extract to kitserver13". Place kits in \kitserver13\GDB\uni