You will need
To edit the files of mkv format without loss of quality is recommended to use Mkvtoolnix. She has a great set of functions necessary to complete the work with the mkv container. Download this program and install it. Now open the directory in which you saved working files this utility and run the file mmg.exe.
Launch the program and click on "Login". Now click the "Add" menu in the "Input files". Select mkv file that you want to break into fragments.
Wait until you see the elements of the video. Open the tab "Global". Check the box next to "Enable splitting". Activate the item "After this size". In the drop-down menu, select the maximum size of a fragment.
Click the "Browse" menu in the "output file Name". Select the folder to store the video files. Click the "Start processing" and wait until the program is completed.
Sometimes to reduce the size of mkv file you can use other functions available in the program. The fact that the mkv container often contains unneeded elements, such as multiple audio language tracks. Click on "Login".
Find the menu "Tracks, chapters and tags" and examine its contents. Uncheck the unnecessary items in the container. After you complete this procedure, click the "Start processing" and wait until you save a new file.
If you want to significantly reduce the size of the video file, convert mkv to avi. To do this, use Total Video Converter or other program. You can also split avi files into separate elements using Mkvtoolnix, another utility or to various web services.