Replace side mirror glass..any help greatly appreciatted

Help! I was driving home and a chunk of tire flew up and hit my side view mirror on my 2001 4runner. The mirror slammed against the door and the actual mirror piece popped out. The glass did not break but popped out of casing and was hanging by wires. I tried to pop back in but afraid of breaking. Does any one know how to replace the actual mirror in the side view mirror (passenger side)? Any help or diagrams of assembly greatly, greatly appreciatted. Thanks!