How can I uninstall an existing Node.js installation and install it again?

First check nodejs existing version and after follow these commands on Ubuntu 22.04.2

node -v
v12.xx

Run the following command to remove both libnode72 and nodejs packages:

sudo apt-get remove libnode72 nodejs

Then, clean up any remaining files from the codevious installations using the following command:

sudo apt-get autoremove

Next, update the package list and upgrade all packages on the system using the following commands:

sudo apt-get update
sudo apt-get upgrade

Now, add the NodeSource repository by running the following command:

curl -sL https://deb.nodesource.com/setup_16.x | sudo -E bash -

Finally, install the latest version of Node.js using the following command:

sudo apt-get install -y nodejs

Finally, you can verify the installation by checking the version of Node.js using the following command:

node -v

This should show you the updated version of Node.js.

v16.20.0