Hey,

Before installing the opencv file as in the instructions, you can run these commands:

sudo apt-get -y purge wolfram-engine

sudo apt-get -y purge libreoffice*

sudo apt-get -y clean

sudo apt-get -y autoremove

this will remove libreoffice and wolfram-engine.

Anyways this is strange as even I have it on 32GB sd card and it works fine.

I hope this helps!