My lo is currently 13 months plus. Need to cut his nap from twice to once per day? If yes, not sure how to do it as he gets cranky when he miss a nap.

I don't think you need to cut his nap, is there any reason why you want to do so? I think it's best to just let them sleep and eat on demand, no real need to adjust their schedules because they'll do so on their own :)