Once again, it's hard to give answer not knowing where you are, so to address your question, I will offer a little bit of timeline for you:
In chapter 6, the pigs change "No animal shall sleep in a bed" by adding with sheets when they move into the farmhouse. This also demonstrates the abandoning of the "All animals are equal"
In chapter 8, the pigs change "No animal shall kill another animal" by adding without cause. This is to excuse the deaths of the animals Napoleon killed for their quote betrayal.
Later in chapter 8, the animals hear Napoleon is dying. He feels better by that afternoon, and then another law is changed, "No animal shall drink alcohol... to excess."
In chapter 10, it is obvious that all are abandoned... commandments 1, 3, and 7 have to do with walking on 2 legs, wearing clothes and being equal. When the animals see the pigs on two legs, they hear the sheep reveal the new maxim: 4 legs good, 2 legs better.
In chapter 9,