Uninstall CUDA 11.0 WSL2 Ubuntu18.04

Hello, I am new to CUDA installation on wsl2. I used sudo apt-get install -y cuda-toolkit-11-0to install CUDA, but it seems like torch is not able to detect this cudatoolkit. Now, I want to completely remove the cuda toolkit. I tried to follow the https://docs.nvidia.com/cuda/cuda-installation-guide-linux/index.html#mandatory-post, but it is not working for me. I tried sudo apt-get --purge remove cuda-11.0and sudo /usr/local/cuda-11-0/bin/cuda-uninstal ler, they give me feed back about unexist package and no such command. The installation guide that I followed is 在WSL中使用GPU:WSL2 + Ubuntu 18.04 + CUDA + Gnome图形界面环境配置_Ashken的博客-CSDN博客
I have gotten stuck on this for long time and if somebody can help me with this, it would be so helpful for me. Thank you very much!