You can delete contact detail in GBooks. Here’s how: 

• Go to Sales and then Customers. 

• To open specific customer details, click on name of customer. 

• Click Contacts tab. 

• To open the popup menu for a specific customer, click on the three dots icon.

• Click Delete. 

• You will be asked to confirm your action in the pop-up that follows. 
• Click on the Confirm button to complete this action.