How do you delete the Pics you sent in message here ?

Delete them from your album.

Go to the message and click on 'edit', delete the image string and then click on 'save'.

If it is a Post you put up 'edit' is in the upper right

If it is a reply to someone else's Post, 'edit' is at the bottom right

You can delete them from you album and they should also delete from your message.

Go through your albums and delete the photo