It should be pretty easy just go to where it says "upload a photo" and then "choose a file" comes up. Next a menu should come up asking where you want to get the pics from, a good choice would be photo library or camera roll. From there you just scroll to find the pic your after and tap it to choose and then wait till it shows up below the reply box and just like that it's attached. Click full image to display large instead of thumbnail size.