1) Select the Messages tab from the top tool bar. Select the existing conversation you would like to send your vCard too or click on the "+Create" button to start a new message.
2) If you created a new message, you will see a list of existing groups and individual contacts. Select the person or group that you would like to text.
3) When you select a contact you will now see any existing conversation with them populate. Click on the business card icon from under the text box.
Your vCard will send automatically.