Whether you’re creating a business letter, a financial report, or your master’s thesis, it’s a sure bet that you’re going to need to go back into your document and do some editing. Word provides a great variety of ways to edit. To edit existing content, you simply select it and make your changes, or, if you prefer, you can type over some existing text to replace it.
If you prefer to type over text without selecting it, use Overtype mode. To turn it on, choose Word Options from the Office menu, and, in the Advanced section, select the Use The Insert Key To Control Overtype Mode option. Click OK, and then press the Insert key to turn on Overtype mode; press Insert again to turn off overtyping.