1. A non-transitory computer readable storage medium storing a computer executable program to be executed in an image forming apparatus for editing an XPS file, the image forming apparatus being configured to receive from a host apparatus a print job and file editing instruction information attached to the print job, the file editing instruction information including first information for specifying the XPS file and second information for designating a method for editing the XPS file, the program being executable to cause the image forming apparatus to execute steps comprising: parsing the print job, received from the host apparatus, so as to read out the first information for specifying the XPS file and the second information for designating the method for editing the XPS file, both included in the file editing instruction information attached to the print job; specifying the XPS file based on the first information read from the print job; decompressing the XPS file to create a decompressed XPS file from the XPS file; editing the decompressed XPS file based on the second information read from the print job; and compressing the edited decompressed XPS file so as to create an edited XPS file that is different from the XPS file received from the host apparatus.