I did. Just went through the same issue. Dealer put steps on, wanted too much for them. I had them remove them. What you are looking at is basically a rivnut that was added with the OEM steps. Just so you know, they are removeable, but it's a pain in the ass!! Took me about 4 hrs to get them off. But, I was using a flathead screwdriver, a hammer, and a dremel.
What you are seeing in the picture is basically a washer that is part of the nut on the inside of the frame. If you can get that washer part cut off, or pry it up from the frame, you can eventually push it through the hole. That's what I had to do. I could then fish the nut out with a magnet. That square spot above the holes is actually just some tape covering up an opening into the frame. That's how I would fish the rivnut out with a magnet. More than likely, your new steps will have you remove that tape anyway to use their new brackets. If you have any other questions, let me know. I can try and help a little more if none of that made any sense.