I suggest you explore “The Forest of Rhetoric” for definitions and examples of rhetorical choices. As far as identifying examples in Wuthering Heights specifically, begin looking for the more general rhetorical choices—for example appeals to ethos, logos, and pathos.
If a character is trying to convince someone through the use of logic, that is an appeal to logos. If a character uses his or her own credibility or reputation to convince another, that is an appeal to ethos. Finally, if emotions are the persuading force, that is an appeal to pathos.
Sections of the text that are dialogue-heavy would be the first I would analyze. Usually, when characters are speaking with one another they are trying to communicate some sort of position on something. This is especially apparent in the face of conflict. Look closely for examples of logical fallacies, tactics a speaker might use to persuade another through faulty reason or manipulation. The most common of these include a “slippery slope” fallacy (where one poor decision leads to a worse and a worse and a worse situation), a “false dilemma” fallacy (where the speaker forces the audience to see a proposed solution as necessary and solitary, while the speaker is clearly omitting other possible solutions or exaggerating the urgency of the situation), and “appeal to tradition” (where a proposition is considered sound for the sole reason that things have always been done a certain way).