Signing Signature Fields in Reader DC

I create PDF documents that need to be digitally signed by a number of people. The signatures do not need to be visible.

I use Acrobat 7 Pro to created the documents and add signature fields for invisible signatures. Those who need to sign, open the PDF in Reader to do so.

In Reader XI there is a signature pane on the left, listing all of the signature fields. To sign, users right click on the appropriate signature field, select Sign Document, enter their password, and save.

Now some users have upgraded to Reader DC and the signature pane is gone. How does one sign a signature field in Reader DC?

Thanks