How do I install the Cloudflare cPanel plugin?
Full instructions can be found here: cPanel Plugin for Hosting Providers.

How do I check which version of the Cloudflare cPanel plugin is installed?
Run the following command on your cPanel server to see the version of the plugin:

grep version /usr/local/cpanel/base/frontend/paper_lantern/cloudflare/config.js

How do I update the Cloudflare cPanel plugin?
Run the following command on your cPanel server to update the plugin:

/usr/local/cpanel/bin/cloudflare_update.sh

If this command doesn't work and you still have an older version of the plugin, please run the
installer manually with the following command:

bash <(curl -s https://raw.githubusercontent.com/cloudflare/CloudFlare-CPanel/master/cloudflare.install.sh) -k [YOUR_HOST_API_KEY] -n '[YOUR_COMPANY_NAME]'

More info on GitHub

How do I uninstall the Cloudflare cPanel plugin?

NOTE: This will not remove zones or users from Cloudflare that have been registered through the plugin.

An uninstall script has been provided to unregister the plugin with cPanel and remove all Cloudflare specific files from the server to deactivate the plugin.

The following set of commands will download the necessary files, execute the uninstall script and ultimately remove the uninstall script as well:

bash <(curl -s https://raw.githubusercontent.com/cloudflare/Cloudflare-CPanel/master/cloudflare.uninstall.sh) && rm -f cloudflare.uninstall.sh

Do I need to install the Wordpress Plugin if I already use the cPanel, or other Cloudflare plugins?
No, you don’t need to install a Wordpress plugin as long as you are already using one of the pre-built Cloudflare extensions. The Cloudflare Wordpress plugin helps get the original IP addresses from visitors commenting on your customer’s site. That’s done automatically in the pre-built plugins.