Slide the phone open. Notice on the edges around the keyboard, there is a thick casing. Remove this casing, instructions below…

Placing two dominant fingers on the back plate where the battery was, use your thumb finger nail (or prying utensil) and place it on the edge of this thin casing. Firmly, push down with your finger nail (prying utensil) around the casing from left to right. Disconnect casing from keyboard section. Flip the phone over and remove it.