Usually something like this is done using mostly the Clone Stamp Tool, along with a little Healing Brush work. For larger areas, such as the tile in this image, I often just copy some of that area and put it on a layer below my working layer. Then I use a layer mask to allow some of that lower area to show through. If it doesn't fit perfectly, you can use the Transform tool to change it's shape a little.
I gave it a try, just for the fun of it

You can check it out by clicking
on this link. Feel free to use this one if you'd like. However, you're the only one who knows exactly how you want the image to look so you'll probably want to work with it a little more. If you're trying to learn more about Photoshop, give it a try yourself. Just take your time, be patient, and you'll be fine.