Open the Word document
Press Ctrl + H
In the Find what box, type the text you want to search for
In the Replace with box, type the new text
Click Find Next to locate each occurrence
Click Replace to change one instance at a time
Click Replace All to change every instance at once
Click More for advanced options if needed
Use Match case to search with exact capitalization
Use Find whole words only to avoid partial matches
Close the Find and Replace window when finished