Apple’s Preview app comes with a handy utility for creating and managing signatures which can be attached to any PDF.
Open the PDF and make sure the Edit Toolbar is visible
Click on Sig in the Edit Toolbar and click the + button to add a new signature. Sign your name in black ink on a white piece of paper and hold it up to your iSight camera, making sure you rest the signature on the blue line. Click Accept when ready and your done.
Now you can click anywhere on the PDF to add your signature. Move it around to place it in the correct position and then Save the document.
You can add other signatures if you need to commit fraud or your signature changes.