General outline:
0) Create a white background and bring you photo in as the second layer.
1) Curve the face lighter.
2) Curve some of the yellow out. A major factor that makes the retro look is the lack of yellow: yellow color tends to fade out over time in the sun first, followed by magenta.
3) Make a layer mask and paint out everything but the mouth, nose tip and eyes (and, if the final hairdo is in the shot already, also keep the hair).
4) Adjust layer mask and color until you got a decent resemblance of the reference image. Note that the nose tip is faded out more than the rest of the remaining features, so you would either curves it lighter individually or make it more transparent with the layer mask.
Kalleheikki Kannisto
Senior Graphic Designer