I'm afraid I don't have a video of the actual procedure but I do trim certain members of my flock.
It's a two person job as you need someone to hold the bird and the other to do the actual trimming. I only take off the feathers that are closet to the eye just to give a little more vision. You just have to be careful with the scissors being so close to the eye. I don't take anything off to close to the skin just the fluffy bits. I'm afraid they don't look pretty when they are done.
The crests can be a limiting thing for the polish and they tend to do better in a run so they can't be sneaked up on.
Good luck with your polands