To edit contact details follow the steps below

1. Tap on "Contacts" in the side panel
2. Choose a contact group, and either use the search or scroll to find your contact
3. Tap on the contact to view the summary and then tap on "View contact" at the bottom of the summary screen.
4. Tap on Edit in the top right to edit the contact details.

Note: The first time you run Save2PDF you will have been asked if Save2PDF could access your contacts. If you tapped "No" you will not be able to see your contacts in this section. To fix this go to the device settings app, scroll down to Save2PDF and then turn on contact access