How to convert a can light to a pendant light! Non-electrical tutorial

We are making progress on the kitchen and one more exciting recent updates is making the old can light over the sink into a really pretty pendant light!

I don't mind can lights for general kitchen lighting and spreading out light over big areas, but above the sink is an opportunity to highlight a really cool fixture! I thought about having an electrician move the power to the wall above the window so I could do a cute brushed brass sconce... but, that costs money, of course, and then we would...