I wasn't suggesting to modify the template.
I was suggesting to apply the template to the pages. open one of the data assist pages, then go to Modify -> Templates -> Apply Template to page and select your template to apply it to the page.
or you could convert the template to a theme, then apply the theme to the page.
What kind of modification are you looking to make to the pages? use Dreamweaver to make any design modifications to the pages, the same as any other page. if you want to change the columns that are used for the insert and update pages, you would need to modify the server behaviors. add or remove any form elements you may need, then open the server behaviors tab (Window -> Server Behaviors) and double click the Insert or Update record behaviors