Jetpack footer "Powered by WordPress"

I’ve asked this question before but haven’t gotten an answer so I’ll try again.

My site (listed below) has jetpack mobile activated. Looks great, love it. However, at the bottom of the mobile site there is a line that says “Proudly Powered by WordPress”. Clicking that link takes you to www.remarpro.com.

I’d like to change that wording to my own wording that leads to a different link.

I’ve gotten advice that jetpack has nothing to do with this, and that I should change my themes footer.php.

I’ve also gotten advice that you should NEVER change your theme files because it will change back when the theme is updated.

I’ve also gotten advice to put some sort of footer code in the CSS to change this. I can do that, but I have no idea what code to put there since I don’t know how to write code.

Can anyone help? Thanks in advance!

My Site: nicenormalfamily.com
My Theme: zbench