The Global Replace window is opened by clicking Replace on the toolbar or choosing Global Replace from the Actions menu within the Search for a String window. You must also have chosen Show Line Where Found when performing the search.

The first step in a Global Replace is to perform the search. When the Global Replace window opens, it will give a warning message if you did not choose Match on whole words. This is because partial word changes can lead to unintended changes.
The global search replace window displays the search string at the top of the window just over the input field where you enter the replacement string.
Two lines are shown for each hit. The top lines is the current value. As you type in the Replace With field, you will see what the code will look like in the second line (the one with the »). You can scroll through all the objects to verify that the change you will be making will give you the desired result.
The Delete button allows you to remove any hits that you do not want changed. Multi-row selection is enabled to make this task easier.
It is highly recommended that you leave the Make backups checkbox checked. This option copies all the libraries that make up the application to your system temporary directory. That way if you accidentally change something you didn't want to change or the change results in compile errors, you can restore the files and try again.
Clicking the Replace button will start the change process.
The Print button allows you to print the proposed changes and review the hard copy.