Sorry, you can't. You need to create a new password.
To do so, use the "Forgot Password" link in your log in page.
This is Mixform's help site. Here you can find articles on how to use Mixform, and check the latest updates and issues. Send me an e-mail if you can't find what you are looking for. --Deb
Contact support for help, or to report any issues at firstname.lastname@example.org