Changing colour of text within an image

I would absolutely recreate the Type layer  — if I could find the font — but with it being so clean, and being so well delineated from the background, you could use a Hue/Saturation adjustment layer.

1. Add the layer from the Adjustments panel
2. You can ether use the dropdown and choose Reds, or click on the little hand icon, and then on the red text.  Ether method will target only the reds in the image, and show in the sliders at the bottom of the Properties panel. This is useful as you can drag those sliders to fin tune the colour range you want to change.
3. Now move the Hue slider to achieve the colour you want. 
4. Fine tune with the Saturation and Lightness sliders.

We mentioned that the background is so clean in your image.  If that was not the case you would have needed to use the Hue/Sat layer mask.

As I said above, recreating the type layer is a no brainer in this instance, but it's still useful to have the tools to use going forward. 

The font is Futura PT Heavy available from Adobe Fonts.

Absolutely, retyping is underrated 😉

If there is an image under the text, and they are merged (not retained as separate layers), you'd have to separate them with selections/masks.

Create a new layer and type new text over it.