Help a knitter out! Knitted pattern with crochet elements

I am making this knitted lion, which has a crochet mane. The mane is one long piece of loop stitch that is sewed on. I don't love that it doesn't cover the full back of the head (you can see it pretty clearly in this project). I know very little about crochet - how difficult would it be to modify this so that the mane covers the entire back of the head, and what sorts of techniques would I need to learn?