This is a complete German translation of all Main and Popup Menus for WinEdt 5.5.
(Translations of the context menus and the hints are still lacking. Contributions welcome!)
Download and extract the zip file to a location of your choice (%b\Config\German seems reasonable), and load the menus with Options | Menu Setup..., click on the "Load From..." button and select the file german.dat.
Beware that this will overwrite all menus and restore the default menu layout of WinEdt 5.5 (albeit in German ...). That is, any menu customisations are lost and you would have to add them once again. Also, you are strongly advised not to use these menus with any other WinEdt version than 5.5.
Menu translation contributed by David Gippner <davidgippnergooglemail.com>