Remove / override functions in child theme

Hi!

I am trying to modify the front page featured areas in my minamaze Child theme. For example, I want to change the featured header to a link. I got it to work when I did it in the parent theme, but I am doing something wrong when I am trying to do it from my Child theme. I copied the 02.homepage.php to the right folder etc…

I found this code in the parent theme header.php

<?php thinkup_input_homepagesection(); ?>

I tried to change it to e.g. thinkup_input_homepagesection1 and also change it in the functions.php file where the code is:

function thinkup_input_homepagesection() {

But I get “Fatal error: Call to undefined function thinkup_input_homepagesection1()” so obviously this is not the right way to do it?

Any suggestions how I can override some parts of e.g. the functions.php file?

Appriciate the help!