You don't need to go very low carb. You do need to eat an adequate amount of protein for your lean mass (samples given in the book) and stop eating inflammatory foods like soy milk or almond butter.
If you want to do primal as a vegetarian, you need to eat legumes (soaked, preferably fermented), dairy and eggs to get the good fats and vitamins. Apart from that, just follow the book. I lost weight eating something like primal, except I was having legume curries for breakfast each day and walking lots. Was having some dairy but had reduced it on cardiologists recommendation. No strenuous exercise at all. The weight fell off and I kept lean mass
Four years Primal with influences from Jaminet & Shanahan and a focus on being anti-inflammatory. Using Primal to treat CVD and prevent stents from blocking free of drugs.
Eat creatures nose-to-tail (animal, fowl, fish, crustacea, molluscs), a large variety of vegetables (raw, cooked and fermented, including safe starches), dairy (cheese & yoghurt), occasional fruit, cocoa, turmeric & red wine