Replacing a text format is very easy. Perform the following steps:
Select the frame that contains the article you want to analyze.
Just go to Edit | Search/Replace or use the Ctrl + F keys. You'll get a dialog divided in two parts. The left-hand side is what you're looking for and the right-hand specifies the changes that you want. Let's say we're not sure we have written Shakespeare correctly each time: it might be shakespeare, shakepeare or some other spelling.
On the left-hand part, select the Text checkbox and write "shakespeare" in the field.
On the right-hand side, select the same Text checkbox and write "Shakespeare".
Click on the Search button. If some text matches, the Replace and Replace All options will be available. The first option replaces only the selected word in the frame. Clicking on it will do the replacement and go to the next occurrence. Replace All just replaces every occurrence without asking you anymore...