Yellowed fingernails?

You can't remove it, you're becoming a simpson, I'm sorry

Soak and scrub them with a little lemon juice or you can scrub with baking soda, I've heard whitening toothpaste can also work but I've never tried that. the lemon and baking soda worked pretty well when this happened to me.

Oh also make sure you use a basecoat when you paint your nails, that can help prevent some of the yellowing.

Do you smoke? because smoking turns your fingernails yellow. If not then it may be a reaction to your nail polish. It also could be a nail infection if you dont look after them properly.

Your nail polish may have caused a fungle nail infection. (where you fingernail ends go yellow) Just pick up some cream from a pharmacy

You could either get a good buffer and lightly take the surface off and buff them up - you need a four sided one from Boots.

You can also buy nail cleaner - its like crystals you put into water and soak your nails in.

rubbing hydrogen peroxide on them with a Q-Tip

Lemon juice with chamomile tea

Soak in (whole) milk them dry with a hair dryer.

hope this helps