this basically removes the unwanted tracks. This will save you 2gb if you remove FLAC audio
this is already coded but please make sure to download mkvtoolnix and place its directory in for example:-
"C:\Program Files\EXAMPLE.exe" (usually its at your main hard disk)

downloads:-
mkvtoolnix:- https://www.fosshub.com/MKVToolNix.html
mediainfo:- https://mediaarea.net/en/MediaInfo/Download

you can also do this with other release with multiple tracks
just follow these steps

Step 1:- download "MKVToolNix" then locate the programe and copy its directory
in here "C:\wherever it is.exe" (usually its at your main hard disk)

Step 2:- place it in some folder with 4 tracks ( jap, eng, signs and songs and full subs and it doesnt have to be 4 it can be more)

Step 3:- locate the track number of each track by using Mediainfo

Step 4:- replace -a !(track number) and -s !(tracking number) to remove it and ---default track (track number) to make it as a default track that is the full subtitles or it can be anything
so it should look something like this (-a ! is audio   -s ! is subtitle)


FOR /F "delims=*" %%A IN ('dir /b *.MKV') DO "C:\Program Files\EXAMPLE FOR STEP 1" -o "fixed_%%A" -a !EXAMPLE FOR STEP 4 -s !EXAMPLE FOR STEP 4 --default-track EXAMPLE FOR STEP 4 --compression -1:none "%%A"
PAUSE

when done right:-
FOR /F "delims=*" %%A IN ('dir /b *.MKV') DO "C:\Program Files\MKVToolNix\mkvmerge.exe" -o "fixed_%%A" -a !1 -s !2 --default-track 3 --compression -1:none "%%A"
PAUSE

incase if there are multiple audios and subtitles
just add a comma to -a ! and -s ! it should so apply to default tracks
FOR /F "delims=*" %%A IN ('dir /b *.MKV') DO "C:\Program Files\MKVToolNix\mkvmerge.exe" -o "fixed_%%A" -a !1,2 -s !3,4 --default-track 5 --compression -1:none "%%A"
PAUSE