Follow the below mentioned steps toDelete a Contact:
Click on the Arrow icon on the right side of "Phonebook" menu
Click on the name of the Group in which the contact is to be deleted
Search the contact to be deleted and click on the checkbox available on the left side of each contact
Press the "Delete Contacts" button
In the delete confirmation window, press the "Delete" button to delete the contact from the current group or press the "Delete from All Groups" button to delete the contact from all groups
See our article about the process of adding a new contact: Click Here