For the first one:
I am very old school and lame, but I actually use the forbidden program named "PAINT"... lol...
I first go and up the contrast & gamma of the picture so all the whites go a hint darker, then I outline the body using a true white, and then i use paint and go into the options and do Black and White. Then it replaces all non-true-whites to black, and leaves only the true white there. Then I invert the image, making the background white and my outline i did, black.
Then I just use the big ol' paint bucket and shade the picture to the colors I want.
The second picture, I brought gamma, contrast, and color corrected it to have more of a yellow and orange feel than the green shade it was originally. Then I outlined it in black, then saved it, and re-contrasted/gamma'd it with the black outline.