1. Open the tool for modifying pdf, and use File-Open to open the PDF file to insert the picture. 2. Browse the files in the webpage, then click the webpage to insert a picture and view the webpage in the edit box. 3. Click "Insert"-"From File" at the top to open the spare picture, and you can see the picture with edit box in the page. 4. Click the deformation point of the edit box with the mouse, and then drag to change the picture to the required size. 5. Finally, don't forget to save the finished file, you can directly output it as a file format.