Just to be clear and avoid others getting into problems....
It's a common thing among new zenner "programmers" to avoid breaking the shrink wrap and just jump in the middle and continue to ride off in both directions. Most of us did that shortly after arrival at Zen Cart.
Problem is, that makes for a multitude of problems down the road. Personally, my "I can do that" quickly turned in to "Why the (*$# did I do that?"
I think others on the forum will agree that modifying a core file for something as simple as layout is just begging for trouble.
It's the nature of our society that we stand in front of a microwave and holler, "Hurry Up!"
You may not see the need for spending the time needed to find the simple (non-core) solution but, it is always time well spent.
This is neither a plug in nor a mod. It is a change in the shipped layout configuration of the cart which is controlled in the stylesheet(s).
While you are free to do whatever you please with Open Source, I just want others to know that this is not the recommended solution and it can be anything from annoying to disastrous upon upgrade.