Are you seeing a specific (like "Unexpected end of archive") when trying to extract these files?
If your files are incomplete or corrupted, it may be easier to use modern official versions that handle installation automatically: Grand.Theft.Auto.Epizodes.From.Liberty.City.par...
: Go back to the original site or folder where you got the files. Archive parts are specifically indexed to work together; a part from a different "repack" or version will not work. Are you seeing a specific (like "Unexpected end