I don't have a video, but I would begin with teaching him to bow.
That one is easy. Pick up one leg, and put a treat at his knee, then pull the treat back, to get him to bend down like that.. once his is comfy with being down, and staying at the bow (soon you won't need to hold his foot) but then you can test him back more.
Then, don't push them over, but simply pull their withers toward you.
Another way is the endorphin tap. It does not hurt the horse, but you may want someone to guide the horse trough it the first three times, then he will drop more quickly, and soon you can just stand at his side, and pull one rein back, then he will fall, and you can mount.
You can go to youtube.com on how to properly do the endorphin tap, as I have only done it once, and don't want to risk any safety.