I've created a new template for our landing pages I can't seem to figure out how to switch templates on already existing landing pages. Any help would be appreciated.
This is not possible.
At least 5 ideas on this item :
The workaround is :
And of course, you will have to edit all smart campaign triggers/filters and all smart list filters that reference the old LP. Start from the "used by" on the old LP.
Also remember that if it is a free-form landing page template, you can change the template when cloning the landing page. It will give you the option to change the template at that time.