1) If your PDF file is the normal file, after openning it in the program, please click the
Edit button, click the text where you want to edit, you will get this blue box around it. Then you can double click the text to change it directly.
2) If your PDF file is the scanned file, after openning it, you will get the following yellow highlighted notice to ask you to
Perform OCR.
So please click it to use, if it detects you have not installed the OCR plugin yet, you will get the following window, you can click the
Install button to install it.
If you have already installed the OCR plugin successfully, after clicking the
Perform OCR button, you will get the following window to choose the
correct languages of your PDF content to perform it. After performing OCR, please click the
Edit button to edit the text.