Array - Remove Duplicate And Original?

I've come unstuck on a certain point. I am trying to find a way to compare two lists and output only lines which are unique. In other words, remove both occurrences of duplicate lines.I'm relatively inexperienced with VB.NET, but this is how far I have managed to come;

Code:
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim LinksList1, LinksList2 As String
LinksList1 = Replace(RichTextBox1.Text, "#vch", "") : LinksList2 = Replace(RichTextBox2.Text, "#vch", "")

[code]....

1) search the array to find duplicates and add them to a second array, then have a second pass to remove anything which matches the second array.

2) search the array for one duplicate and store it, then search the array again to remove the duplicates, and run that process until there are no more duplicates.

Then again, I could be going about this completely the wrong way. If that's the case, feel free to knock some sense into me.