Step 1: Log in to Google Docs with your Google account.

Step 2: To upload your PDF file, click the small file icon.

Step 3: Once your PDF is uploaded, it will open in your web browser automatically. Select 'Google Docs' from the drop-down menu by clicking the small triangle tab.

Step 4: The PDF will be routed to Google Docs' online editing page. You can now add whatever text you want to the PDF. Remember to polish your texts with the editing toolbar