How can I edit contact details?
To add/edit contacts and contact details you need to Open the Questionnaire:

And then go to the contact details section (or however you may have renamed that):

From the list, look for the contact you want to Edit or Delete.

Note: From the Contact Details section the client can delete contacts (other than themselves) up until the point they submit the questionnaire. After submission, only the attorney is able to delete contacts.
Frequently Asked Questions
Why can't I edit contacts from the matter details screen?
The matter details screen only shows the contacts. To add, edit, or delete contacts, open the questionnaire and go to the Contact Details section (or whatever you renamed it to).
Can my client delete contacts?
Yes, from the Contact Details section the client can delete contacts other than themselves, up until they submit the questionnaire. After submission, only the attorney can delete contacts.