video creation

I want to take a youtube video and clip part of it, then paste heads over the characters (for a meme video). How can I do this; or is there anywhere online where I can find someone to make it for me? Edit: This is still unsolved.

Hi all, i just bought new speakers (Logitech z906) and hooked them up via analog connections. Everything working fine but i figured out that in order for them to decode DTS properly i need to setup a digital connection. So i googled and i am overwhelmed by so many different terminologies...