wordpress theme customization question

Hi, I started to manage a wordpress websie of a customer.
It uses Wordpress Custom Form 7 (wpcf7).

There is a form that it is included in several pages.
You can see one here:
(the form on the right)

My question is:
I need to replace it with a Gravity forms form. How can I do that? (I cannot find where this wpcf7 was incuded!!)