AlMedhi,
Mate, I am dumb founded. I got it to work once and not again since, could you please check I am doing it correctly for me.

sudo cp /usr/share/themes/ /home/user/MyDocs/dthemenight-themedir
"dthemenight-themedir" being the theme name under /usr/share/themes/.
Do I need to create the folder first under MyDocs:
mkdir MyDocs/dthemenight-themedir ?