Version 1.1
Extract the Move With Arrow Keys1.1.rar using WinRAR extractor.
If you use JSGME for your mods, place the folder Move With Arrow Keys, that was just extracted, in the directory C:/Ubisoft/Silent Hunter 5/Mods/ and activate with JSGME
If you do not use JSGME, go to directory C:/Ubisoft/Silent Hunter 5/data/Cfg and backup your commands.cfg file. Then go into the mod folder Move With Arrow Keys/data/Cfg and copy this commands.cfg over the one in your silent hunter directory.
I recommend JSGME however since it's far easier to use and eliminates the risk of losing files should you forget to back them up.