The XPS executable is a MS-DOS utility so just open a DOS-Box (MS-DOS Prompt) and enter the following at the command line prompt:
USAGE:  XPS <PatchName.XPS> [<Filesname.ISO>]

Examples:

To patch an ISO CD-Image, enter:
   XPS  PatchName.XPS   Filename.ISO

To display the information about the XPS file, enter:
   XPS  PatchName.XPS

Also included in the latest version is a file called: XPSFORM.ASM
This is an example how to create a XPS file. Some assembler knowledge is needed to use it.