Activate the type tool. Set the text options in the options bar to a heavy block font like Impact, a size of 160 pt (type it in), and centered alignment. Click in the image, type your text, and position it as shown here. Leave enough space below the text for its reflection.
It is best to use a word that does not contain descending characters like j or g. If you must, you may need to use upper-case depending on the font chosen.
