If it isn't there already, go to window > layers to bring up the layers window.
1. Go to layer > new adjustment layer > levels and fill this in: Input levels: 39, 1.38, 239 Output levels: 15, 255
2. Go to layers > new fill layer > solid colour and put the hex code #252D3D in the text box. Set this layer to lighten at 60% opacity.
3. Go to layers > new adjustment layer > selective colour, select "absolute" and fill these in (the colours are on the drop-down list):
RED -35, -13, -31, +4
YELLOW -17, -19, -17, -7
GREEN -57, +13, -18, -3
MAGENTA -22, -25, +15, +3
WHITE -21, -3, 0, 0
NEUTRAL -6, -18, -24, +12
BLACK +27, 0, -6, -1
4. Go to layer > new adjustment layer > colour balance, select "preserve luminosity" and fill this in: Shadows: -18, -17, -14 Midtones: -26, +11, +2 Highlights: +14, -4, -4
5. Go to layer > merge visible to merge the layers.
6. Duplicate your background layer by right clicking on it and selecting "duplicate layer", or simply dragging it to the small icon that looks like a folded piece of paper on the layers window. Set it to soft light at 50% opacity.
7. Go to layers > new adjustment layer > curves and select blue on the drop down list. Click anywhere on the grid and fill this in: Input: 34 Output: 49 Now click on the grid again, to make a new point. Input: 227 Output: 223
8. Duplicate your background layer again and drag it to the top of the list. Set it to multiply at 25% opacity.