You can export template from RVsitebuilder to edit code/html and import back to your project again.
1. In Step 1 , mouse hover on the template you want. The download icon will appear. Just simply click it and download to your computer.
2. Extract the template .zip file in your computer, and open file “index.htm” to custom your code/html.
3. Once finished editing your custom code. Save and compress the file as .zip.
4. Import back to your RVsitebuilder in Step 1 -> Import template.