Introduction
If you need to disable the Cloudflare proxy service, you can do it through the Cloudflare interface. When Cloudflare is enabled and proxied, accessing a site shows a different IP than what the domain resolves to. An example of why this should be done is if your website has a strange issue, and disabling the Cloudflare proxy allows you to determine whether or not the issue is related to Cloudflare.
Procedure
To disable Cloudflare, toggle the Proxied option via the Cloudflare Proxy Toggle in their interface, as seen here: