The easiest way would of course be to try and find the typeface the text is set in, and reproduce the word. Barring that possibility, you could try the following:
- Make your image a regular layer (as in: not the background)
- Use the Magic Wand tool set to a somewhat generous tolerance (~32) and select all of the white letterforms (use shift)+click to add to your selection).
- Click on the 'Add layer mask' button to make your selection into a mask for the layer. You'll find the button on the bottom om the layers panel.
This will yield your text, with some darkish edges where the Magic Wand took along some black pixels and made them partially opaque:
- Then, add a color overlay in white to your layer. You can reach the color overlay by right-clicking on the layer in the layers palette and choosing 'Blending options'. To edit the colour and the settings of the overlay, remember to click on the 'color overlay' word on the left-hand list, not just the checkmark.
This will cover all of the visible pixels of the layer in white, leaving the partial transparency of the greyish edges intact, but making them white: