Well, this isn't the best way, but is "any"
I've made a very tiny program with VB6 (works in WinXP SP3) to check and replace (if needed) the three files i know: .pot, widget and languages.
The settings.ini file is quite simple:
sourcefolder: the folder where the files to compare are
destfolder: the folder where the new files will be downloaded (could be the same as sourcefolder if you don't want to know which are the changes)
file: each one of the urls
(those lines can't be reorder. "sourcefolder" and "destfolder" need to be before "file")
And finally, with "checker h" the program runs in the background.