That would be a very hard clip to do what you're trying to do to.
Your green is uneven, even in the background. You have WAY too much reflected green in the lower foreground to get the green out, and the 'blacks' aren't even close to black. Let alone the out-of-focus caused blending between the black ground and the background is another nightmare for keying.
I work with some Ae wizards. This would be a challenge for them, in Ae.
I would suggest it might be easier to reshoot, with more distance between green screen and foreground subject, more even light on green screen, and some 'clean' backlighting on the foreground so no green reflecting appears.