I answered same question before: Raspberry pi remote access active session
You need to install x11vnc daemon on the linux distro with runs on Pi. Then run that command;
x11vnc -display :0 -usepw -noxdamage -ncache 10 -ncache_cr -listen IP_of_pi -allow allowed_ip_address
After ran the command, connect to pi with any VNC client.
