Both pea protein and soy protein products with comparable protein to kcal ratios are available from the company I buy my protein from.
I'm not vegan, so I've never bothered trying them, but it doesn't seem like it'd be a big problem.
My concern (see my other comment) would be that the diet shown certainly is extremely high calorie, and it looks like it'd be pretty much all nasty shakes to get it down to a more normal level with the same amount of protein.
(EDIT: Note, this would only really be an issue if you do heavy resistance training, as the protein level in that diet is very high for someone who isn't doing weight lifting)