Video Textures Play & Replay for DUMMIES

I’m looking to create what amounts to a simple virtual screen in my game, which starts playing a video when triggered (say, by pressing a key) and plays all the way to the end until the key can be pressed again to start it over.

I’m a noobie to Blender and don’t know Python.

Also, I’ve tried using Monster’s Dynamic Texture, but I’m afraid I haven’t been able to understand how it works on my own.

Could anyone explain to me like to a 5 year old how to obtain this, with or without Monster’s API?

On a more serious note, also see tutorialsforblender3d’s tutorial on the problem: