All editions of Microsoft Word offer a feature called Find and Replace. Use this tool to search for a specific word, number, or phrase in a document and replace it with something else. You can also perform multiple replacements at once, such as changing a name or correcting something you've consistently misspelled. Also use it to replace numbers or punctuation marks, and to capitalize or uncapitalize words.
Microsoft Word's Find and Replace dialog box, in its simplest form, asks you to type the word you're looking for and the word you want to replace it with. Then click Replace and let Word change all the entries for you, or go through them one by one.
To open the tool, press Ctrl+H (Cmd+H on Mac).
The Find and Replace function does not respect capitalization unless you specifically tell it to. To get to that option, click the More option in the Find and Replace dialog box: