Please provide quotations from Romeo and Juliet about judging a person by their name.

In the balcony scene, Juliet says,

'Tis but thy name that is my enemy.
Thou art thyself, though not a Montague.
What's Montague? It is nor hand, nor foot,
Nor arm, nor face. [...]
What's in a name?  That which we call a rose
By any other word would smell as sweet.  (2.2.41-47)

She means that it is only Romeo's name that is her enemy; she doesn't hate him for himself, but only for his name, and his name isn't really a part of him.  His name is not a part of his body, like an arm or foot.  She thinks that, ultimately, a name is meaningless because a thing would still be what it is, even if it were called something different.  Thus, one cannot judge a person by their name because a name is not essential to the person.

Romeo says that if Juliet loves him, he'll "be new baptized. / Henceforth [he] never will be Romeo" (2.2.54-55).  Thus, he seems to agree that names mean relatively little in comparison to other, more important, considerations like love.  He'd rather be loved than be called a Montague.  Likewise, if his name is hateful to Juliet, he says that it's hateful to him, too, and that if he had it written down, he "would tear the word" (2.2.62).  He would give up any name for her.  Again, if names are meaningless and so easy to shirk, then they really are not an appropriate basis for judging another.