What's your problem?
You want to remove or extract a part of a video.
You could download, install and/or buy some advanced editing software which has such feature (like Adobe Premiere Pro), but it takes a lot of time and energy, especially if you are working with several, long videos and the software has to decodes and re-encodes the files every time.
The solution: FFmpeg.
FFmpeg is a complete, cross-platform solution to record, convert and stream audio and video.
Ffmpeg has a simple command that lets you edit the file as you will, almost instantaneously. It also works for audio files.
1. Download the package
=> Windows
=> Mac
=> Linux
2. How to use it ?
Just run the following line from your command prompt
ffmpeg -i InputPath.mp4 -ss 00:10:00 -t 00:00:05 -acodec copy -vcodec copy OutputPath.mp4
Where -i is the path to your file.
-ss is the start position in Hours:Minutes:Seconds
-t is how long a clip you want - again in HH:MM:SS
The acodec and vcodec tells ffmpeg just to copy the file without changing its other audio and video properties.
That's about the fastest you can get it done.