no probs man i haveno idea where to get a video of turtles but theres a short bit of them on the clip of we are electric by flying steps but its a birds eye view so it dont really help much, il have a look around for a clip tho.
first u have to know turtles... when u know how to do that u have to hold in this position for about 20 sec more or less.-. then u can practice glides..