Steps:
1. Open the password recovery of AP PDF, click "Add File", find the PDF document to be decrypted in the directory, and confirm; Then set the decrypted output path and name the new document (for example, "1"); Click "Decrypt PDF" on the toolbar, and the software begins to decrypt it. After decryption, a new file named "1.pdf" will appear in the set output path.
2. Open the Foxit PDF editor, click File-Open, and open the "1.pdf" which was just restored with the password of AP PDF.
3. Click Document-Export Page to open the dialog box. Set the output path, the file name of the new document and the range of exported page numbers (for example, from the first page to the last page) in the dialog box, and then click OK to start the export.
4. After the export is completed, a new file named "2.pdf" will appear in the set output path. When you open this file with Acrobat, you will find that the original digital signature has been deleted, the security method of the document has been changed to "No Security Settings", and all functions previously disabled by the producer have been reset to "Allow". At this point, the digital signature of the document is perfectly deleted.