Desktop: Click on the purple My Dashboard icon. On the right side of your screen, click on Messages. Once you click messages, you will view a list of all messages received. Click the trashcan to delete the message.
Mobile: On the top right corner of your screen, you will see 3 black dots. Click here to view a drop down. Within the drop down you will see Messages - click.
Once you click to view your messages, you will see a list of all messages. To the right of the message there will be a trashcan. You can click here to delete the message. OR you can click on the message first to view it. While viewing the message, there is also an option to delete the chat. Click the 3 dots, there will be a drop down with options. Click Delete Chat.