Right-click on Part 1 and select "Extract Here." The software will automatically pull data from Part 2 and the others to recreate the full game folder.
Be very cautious when downloading .rar files from third-party sites. These files are common vectors for malware. Always scan the extracted folder with updated antivirus software before running any .exe files. Common Issues Medal.of.Honor.part2.rar
You cannot extract Part 2 by itself. You must have Medal.of.Honor.part1.rar and any subsequent parts in the same directory. Right-click on Part 1 and select "Extract Here