Pastel Pink Hair? <.<

Okay, I'm planning to dye my hair pastel pink. I'm using Special Effects Cupcake Pink dye. I know that in order to attain the pastel color I have to mix the dye with a white conditioner to dilute the dye. I do have a few questions though, and was wondering if anyone on here has had any experience in this area. xD I need to know the approximate amount of dye to mix with the conditioner, how I might remove yellow tones from my hair to make the pastel take better? My hair is blonde, with areas that have yellowish tones in it (And I do believe that will limit the pastel color).

I'm attaching images. One of my current hair color, and one of the color I wish to attain. Any help would be very much appreciated. Thanks! xxxx <3

Also: Link to where the image of the girl with pastel pink hair came from: http://25.media.tumblr.com/tumblr_me6w542JBy1roidpvo1_500.jpg