The work involves:
Changing the menu and navigation to match the new template.
Changing all the existing HTML view pages to use the CSS and JS components from the new template.
Changing all the HTML elements on each page to use the new CSS classes and CSS styling from the new template.
Changing the layout of the elements on the screen, if necessary.
There are 32 HTML files with about 22,000 lines of HTML in total.
Ensuring that all placeholders in the HTML views are untouched.
The end result must be a new site that has a new look-and-feel but that works the same as the old site.