Open up the picture in Photofiltre. Click on the Clone Stamp Tool and set your settings as mine.
Now on your picture click CTRL while clicking on the part of your picture that you want to clone (copy). If you get confused a pop up will show up and will most probably help you out.
Then just drag your mouse around for where you want the clone to be. It seems confusing but you’ll get the hang of it. Then you can add effects or whatever you want.