Modern contact lenses are made of material that cannot break or crack but it can get torn. Before starting with removing a torn contact lens from the eye, it is a good idea to ask someone for assistance.
First locate the lens and opening the eye as wide as possible, move your eyeballs in a circular movement till the lens is visible.
Add saline eye water to add flexibility to the eye and then grab the lens with your index finger and thumb.
In case the lens is not visible, hold a glass of saline eye solution and cover the eye tightly forming a seal. Then bathe the eye with this solution. Move the eyelid in circular motion and the pieces of the lens will come out.
If in any doubt or the problem persists, always consult a professional.