Do you have access to Acrobat?
I believe this is a form that you created with FormsCentral and then you downloaded/saved as PDF via the "Save Submission-Enabled PDF" button via the Distribute Tab.
Please select via FormsCentral app main menu:
- File -> Save As PDF Form... and then
- when you get the dialog "Would you like your PDF form to collect responses online in the "View Responses" tab?" select "Don't Collect Responses" button.
This will save the PDF form without the Submit button/link.