STEP 1
Run PDF Super Toolkit, click on Digital Signature.
STEP 2
Click on Browse button at the top of the window to choose PDF file from your machine.
STEP 3
Click on Browse button at the middle of the window to select PFX file, enter the password of the PFX file.
STEP 4
Click on Browse button at the bottom of the window to select destination path to save output PDF file.
STEP 5
Click on Process button to save signed document to output PDF file. A message Successfully sign file will be displayed after processing, press Yes to open the output PDF file with system default PDF viewer.