You can quickly search for every occurrence of a specific word or phrase into your document.  To display this dialog you must be in Text View mode.  Then, click on the Find button in the Editing group.

Use this dialog to find text or other items in your XML document:

You can automatically replace a word or phrase with another using the Replace dialog:

To display this dialog you must be in Text View mode and click on the Replace button in the Editing group.

Check Match whole word only to only search or replace the entire words that use the same text as typed in the Find what text box.  If unchecked, partial words will be searched or replaced.

Match case assures for the search to be case sensitive.