The simplest thing to do would be to crop the photo.  Simply crop out me and most of the sky (taking my hand with it).  But that would be part of the cropping lesson.  So let's do this the hard way.  One thing to note in this picture is all that sky.  If my hand wasn't there what would you see?  More sky!!!  And the sky is such a uniform blue.  If I took a section of sky from this photo and moved it somewhere else, could you tell?  Let's find out.

First we need the FREEHAND tool.  It's another tool that does not have a drop down menu selection.  It seems that most of the tools, on that row of buttons, don't have another way of selecting them.  And if you are using a TOOL, there is a TOOL OPTIONS toggle.  Select the TOOL OPTIONS toggle and it will produce a special box for the TOOLS options.  Don't worry, it will make more sense as we go on.

OK, there is the TOOL OPTIONS box and I have selected the FREEHAND tool.  Find an area of the photo that has the same background as what you expect to see.  That's confusing.  I've selected a portion of the photo that has the same color of sky where my hand is.

Next, select the COPY feature from the EDIT menu (you can also use the COPY button on the toolbar).  This will copy the area you selected and put it in memory.

Now let's use that copy.  Go back to the EDIT menu and select PASTE/AS NEW SELECTION.  Creating a 'new selection" will put that copied area under the mouse cursor.  Move the selection to its new location (over my hand) and click the right mouse button.  It will be released wherever you placed it. 

Now Guido really does a leash sticking out of his head.  I could have selected a larger area and covered more of the leash but this was just an example.  Notice that my selected area isn't a perfect circle or square.  The human eye has a habit of being attracted to them.  So, a wavy line is easier to hide.