The Terms & Conditions can be signed by clicking on the green 'VIEW & SIGN' button in the Terms & Conditions section.  The 'Terms' can be viewed on the 'Terms' tab as highlighted below and the document that displays is based on the option selected in the 'Terms & Conditions' drop down.  The T&C's will display here regardless of whether you create them as a PDF or as HTML Terms and Conditions

Once you have signed via the 'Signatures' tab the signatures are date stamped and the 'Terms Accepted' check box is ticked.  Read more about setting up Test Drive T&C's HERE.