Login to your domain registrar account and go to the page for administering your DNS settings. This may be called, DNS Settings, DNS Management, Name Server Management or something else.
You will find a list of DNS records. There might be all sorts of DNS records already set up - such as A records, CNAME records, MX records and more. If you already have A records set up you need to delete them.
Next, you need to create a new DNS record with the following settings:
Optionally, if your domain registrar allows it (many don't), you can create an ALIAS or ANAME record on the root domain:
Hostname: @ (or leave empty)
Type: ALIAS or ANAME
You will now have two records looking like:
@ ANAME dns.clubbuzz.co.uk
www CNAME dns.clubbuzz.co.uk
Don't worry if your registrar doesn't allow ALIAS or ANAME records on the root domain, your site will still work.