1.) Download/install MKVExtract GUI2 and YAMB.
2.) Open up MKVExtract GUI2, click on the browse button (the ... button by input file) and choose the MKV.
3.) Check/Tick the audio and video streams.
4.) Check/Tick Use source dir for output.
5.) Click Extract.
6.) After both streams have been extracted, close MKVExtract GUI2 and then open up YAMB.
7.) Go to Creation, and double click on "Click to create a MP4 file with multiple audio, video, subtitle and chapter streams".
8.) Click on Add, and select the video stream.
9.) Click on Add, and select the audio stream(s).
10.) Rename the output file if you desire, then click on Next.
11.) Wait for the muxing to complete, then click on finish and yes.
12.) You're done, congrats.
