How to set wide aperture?

I have a Nikon d5100.
I want to shoot with the sun behind my subject (hitting my camera) in the golden hour. I read that I need to set wide aperture, how can I do that?
Please don't say "go read your manual" because my manual is in a language I'm not fluent with.

Your manual should be available for free on line in a language you understand.

Meanwhile, set your camera to aperture priority and use the lowest number (which is actually the largest because it is a whole number) such as 2.8, 3.5 or whatever your lens has.

Set your camera to "Aperture Preferred" mode (A).

Then, as you are composing the scene through the viewfinder, use the thumbwheel to adjust the aperture setting. "Wide" translates into a small f'-number. Your ability to select a wide aperture will be limited by the lens you are using. I don't know if your lens is inherently 'wide enough' to achieve the effect you are looking for.

Here you can download the manual in English:
http://support.nikonusa.com/app/answers/detail/a_id/17325/~/user's-manual---d5100---guide-to-digital-photography