I want to delete the image in the Messenger
First open up the Messenger app, and select the conversation that has the pictures that you want to delete and get rid of.
Then you are going to press on Details in blue in the upper right hand corner. Scroll down until you see the Attachments.
Then you are going to tap and hold on one of the images until you see Copy, Delete and More appear.
Tap on More and select all of the images you want to delete.
Then you are going to press on the blue trash can in the lower right hand corner to delete them. To confirm you want to delete them, you are going to press the red words Delete Attachments.