So I've looked around how to do this but so far haven't had luck. I've tried the command
sudo apt-get purge matlab-support
And then I tried this one, but I don't have a folder "lmdown". I try just
sudo rm -rf /usr/local/MATLAB/2019b
But that doesn't remove it. How do I get rid of it? It's taking up a lot of space (it was giving me issues, so I downloaded it twice... now it's quite annoying).