As of right now, Hotcakes only provides the services necessary to run your website. We don't provide e-mail services, for example. So updating your DNS to be able to use Hotcakes is quite simple.
You should only need to update the two Host (or "A") records for your domain. They might look something like "example.com" and "www.example.com". You'll need to change the IP address from the current IP address, to the new IP address assigned to your Hotcakes site.
The exact steps required to apply this update will depend on the DNS provider you're using. Here are a few links of common providers for your convenience.
Please DO NOT make this change until you're absolutely ready to switch over from your old hosting location, to the new one here at Hotcakes.
Also, you should be aware that some customers may still end up on the old site for up to 24 hours. This is nothing that we have any control over. It may take that long for the DNS servers in the area of some customers to update.