It's a little different than changing the existing text in a PDF file, but it's still simple - simply follow the steps below:
- In the Acrobat PDF Editor, open your file.
- On the right side of the screen, click Fill & Sign.
- Select the Add Text tool, which is represented by an upper-case 'A' and a lower-case 'b.'
- Start typing anywhere in the PDF where you'd like to add text.