Websites - How do I switch from one template to another?
If you have an existing DPG website and you want to re-design it by switching to a different template or make other big changes, you can simply create a new website that you develop in parallel to the current one.
This allows your site to be online and completely stable so that your visitors always get the best browsing experience. Meanwhile, you can experiment as much as you like with your new site and perfect the new design without any downtime. DPG allows you to add the same images to multiple sites, so you can re-arrange your work as much as you like.
Once you're ready to go live, all you need to do is switch the domain name across and the change will be immediate.
Check here for a guide to Switching Templates.