I am not sure a video would be that helpful. You just need to get a CD of someone blowing the call and listen and try to reproduce those sounds. Maybe I am wrong but since the call is inside your mouth I think its kinda like hard to show someone how exactly it's done.
Primos make some good instructional cd's that come with their calls.
Haven't seen his video but Shane Hendershot and Zink calls has a instructional video on mouth calls. All I know is that guy sounds more like a turkey than the real thing.
but all you have to do is put the call on top of your mouth...then put your tongue on the latex part...then you blow like your exhaling.......... and listen to a turkey hunting show and listen to the birds/hunters and mimic them