Choose a text to deconstruct. Focus on a text you know well as you practice textual deconstruction. To avoid bias, though, it's best to focus on a text that isn't personally important to you.
Understand the intended meaning of the text, or the accepted meaning of the text. For example, if you have access to the author's opinions of the text's meanings, focus on this as you read; if a classic text is generally interpreted or taught in a particular way, use this information as you read.
Locate ways in which the text doesn't conform to its stated or accepted meaning. A classic example of this is Twain's "The Adventures of Huckleberry Finn," which has generally been accepted as an anti-slavery book. However, Huck and Tom continue to pretend Jim is a slave after he attains freedom. They treat him cruelly, as if he is their slave. This section of the book doesn't conform to the accepted meaning.
Find tensions and contradictions within the text, looking for ideas that don't readily match other ideas present in the text. Those who deconstruct texts say that they don't actually deconstruct texts; instead, the texts deconstruct themselves through their own instability.
Seek out the text's assumptions. Look for what it presents as normal, natural, apparent or primary. Likewise, seek out where the text sets up a distinct binary opposition between two categories. For example, it might insist that there is a firm distinction between gay sexuality and straight sexuality, or it may indicate that heterosexuality is natural, while homosexuality is a perversion.
Demonstrate how binaries and hierarchies break down under scrutiny by showing how the text's idea of "normal, natural, apparent or primary" is actually none of those things, or by showing how one thing (such as heterosexuality) needs another (homosexuality) to define itself against. Without both categories, neither one makes much sense.