Open the Messages app
Open the conversation
Tap and hold the text message
Tap More
Select the message
Tap Delete
Tap Delete Message
To delete an entire conversation, swipe left on the conversation
Tap Delete
Tap Delete again to confirm
Open the Messages app
Open the conversation
Tap and hold the text message
Tap More
Select the message
Tap Delete
Tap Delete Message
To delete an entire conversation, swipe left on the conversation
Tap Delete
Tap Delete again to confirm