All you have to do is either
- Overview > Pause the cloudflare.
- Go to DNS > Grey out the A record pointing to IP
Once you do this, cloudflare becomes DNS server routing all your traffic to the host ip address. Before you do that remember your SSL installed at the local server must be working properly. You dont need to change name server records.
After you do this, Cloudflare services such as SSL certificates, Page Rules, WAF firewall rules, Caching will not work.