Summarize the warning about svn checkout over existing directories in a

one-sentence introduction paragraph.

en_US.ISO8859-1/books/handbook/mirrors/chapter.xml

@@ -491,9 +491,10 @@ Comment out for now until these can be verified.
 	  copy</emphasis>.</para>
 
       <warning>
-	<para>If the local directory already exists but was not
-	  created by <command>svn</command>, rename or delete it
-	  before the checkout.  Checkout over an existing
+	<para><emphasis>Move or delete the local directory before
+	    using <command>checkout</command>.</emphasis></para>
+
+	<para>Checkout over an existing
 	  non-<command>svn</command> directory can cause conflicts
 	  between the existing files and those brought in from the
 	  repository.</para>