Cannot purge nvidia drivers

I'm trying to reinstall nvidia drivers + cuda. I've installed drivers for 440, but accidentally installed cuda-11 which installed drivers for 450 and messed my system up. Now am trying to purge all of my drivers via sudo apt-get remove --purge '^nvidia-.*'. However, I get the following error

You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies: cuda-drivers-450 : Depends: libnvidia-compute-450 (>= 450.36.06) but it is not going to be installed Depends: nvidia-compute-utils-450 (>= 450.36.06) but it is not going to be installed Depends: nvidia-dkms-450 (>= 450.36.06) but it is not going to be installed Depends: nvidia-driver-450 (>= 450.36.06) but it is not going to be installed Depends: nvidia-kernel-common-450 (>= 450.36.06) but it is not going to be installed Depends: nvidia-kernel-source-450 (>= 450.36.06) but it is not going to be installed Depends: nvidia-utils-450 (>= 450.36.06) but it is not going to be installed Depends: nvidia-modprobe (>= 450.36.06) Depends: nvidia-settings (>= 450.36.06) but it is not going to be installed libnvidia-decode-450 : Depends: libnvidia-compute-450 (= 450.36.06-0ubuntu1) but it is not going to be installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

Regardless what I do, whether I run apt --fix-broken install or purge other packages, I seem to always get this error.

I've seen quite a few posts run into similar problems (see links below) -- but the only solutions that I've seen is to reinstall ubuntu (which is not a preferable option). I have seen one post that suggests how to manually remove broken packages, has anyone had any luck, with this?

NVIDIA driver problem after apt upgrade ubuntu 18.04

2 Answers

Actually, I think I fixed the problem. I was able to manually traverse the dependency tree

sudo dpkg --remove --force-remove-reinstreq cuda
sudo dpkg --remove --force-remove-reinstreq cuda-11-0
sudo dpkg --remove --force-remove-reinstreq cuda-runtime-11-0
sudo dpkg --remove --force-remove-reinstreq cuda-demo-suite-11-0
sudo dpkg --remove --force-remove-reinstreq nvidia-driver-450
sudo dpkg --remove --force-remove-reinstreq cuda-drivers-450
sudo dpkg --remove --force-remove-reinstreq nvidia-driver-450
sudo apt purge *nvidia*

So now I am able to remove all of the nvidia drivers. grrr

I installed the driver from Nvidia download. I call below

sudo nvidia-uninstall

It deletes all the nvidia driver completely.