This is purely a guess on my part... but I suspect that the audio of this film actually has the two languages on separate audio tracks, which have transferred to your computer as the two "sides" of a stereo audio track. e.g. the German version might be on the "left" channel and the English version on the "right". In which case, you need to remove or mute the channel that is in German and then convert the remaining English audio to mono (so that it plays from both speakers of a stereo system). I don't have Video Easy so can't tell you exactly how to do this but hopefully the installed Help file will give you some ideas.
Just as an aside: do be aware that the digitising of a commercially-released video tape could be viewed as a copyright infringement by the original producer.