Variant 1 (for noobs):
Download start.exe from http://misc.openkore.com and unpack to the same folder where packet_extract.pl is placed.
Copy target .exe file to the same folder where packet_extract.pl is placed.
Run packet_extract.bat to save extracted packets to text file.
Variant 2 (for profi):
Download start.exe from http://misc.openkore.com and unpack to the same folder where packet_extract.pl is placed (optional).
Copy target .exe file to the same folder where packet_extract.pl is placed.
Run start.exe ! packet_extract.pl your_exe_name.exe or perl packet_extract.pl your_exe_name.exe to generate "extractor.exe".
Run extractor.exe > recvpackets.txt to save extracted packets to text file.