Again type the words The quick brown fox jumps over the lazy dog into the yellow box.

 

Now use the left pointing arrow (of the three arrows shown above) to move back through the text.

Use the right pointing arrow to move back again.  Move back and forth until you line-up at the end of the word fox

Now use the Back-space key to delete the word fox and instead type in the word squirrel

Use the left and right arrows to move through the text, add in the extra symbols etc... until your text looks like this: