Need help with using variables in a modal

[laduenni]

In the checkout page, at step 4 (payment) as you know there is a form area with a checkbox and the text of "I agree to the [terms of service] and will adhere to them unconditionally."

So I need to do two things: 

(1) I need to change it to this text: "I approve the [pre-information form] and the [Distance Sales Agreement]." Both "pre-information form" and the "distance sales agreement" will open two different modal boxes with two different pages that I created.

(2) Each agreement has a field that shows the name and several information about the buyer. So when each modal boxes open up, those fields need to be dynamically populated with the information of the current buyer. I figured that can be achieved by adjusting the corresponding controller by using variables but, how can I do them?

[NemoPS]

Can you share the page? For the latter I think you will have to use javascript. The first one should be in the back office translations page