How can I write on a protected PDF?

Kathy is trying to use a PDF form, but it's locked. How can she write to it and fill in the forms? Leo says there are products that can do it, but she can't do it with Adobe Reader. She'll need a program that can open and edit the PDF. Leo recommends FoxIt. It's free and she can use it to edit protected PDFs. She can then save it out with no problem.