This is a good question. It is first important to discuss what the death of the author means.
It is taken from an article written in 1967 by Roland Barthes. He argued against a traditional understanding of reading a text. He stated in this article that the author's intent and biographical context were not important in the process of interpreting a text. Instead, Barthes argues that the text and the author are separate. In other words, the text has a life of its own.
If we apply this insight into Animal Farm, all we need to do is read the text and interpret it. When we do this, we will interpret it from our perspective and experience. In fact, most students today probably will know nothing about Orwell, his political views, and what is happening in Russia and Europe. So, in effect, many modern readers are looking at a text apart from the author.
So, if you want to apply Barthes' insight, just read the text and if you don't know much about Orwell, that is ideal. To take another step, read into it whatever you desire.