A method of upgrading a first software file stored at a wireless communication device so that the wireless communication device is provided with a second software file that is an upgraded version of the first software file, and also a wireless communication device and system, are disclosed. In at least one embodiment, the method includes receiving a software upgrade file, where the software upgrade file includes second-order difference information. The method also includes storing the upgrade file in a memory portion associated with the wireless communication device, and generating the second software file based upon the upgrade file, the first software file, and additional information. The additional information includes at least one of a pattern file representative of assumed differences between the first and second software files and at least some first-order difference information representative of at least some actual differences between the first and second software files.