How do you adjust the clutch on a Nissan Sentra 2001?

I recently started having problems with the clutch. The friction point is getting higher up on the pedal. I thought the clutch itself could be worn out, but I don't have any other symptoms of a worn clutch: no trouble shifting, shifting and engaging/disengaging does not make any weird noises, the engine does not rev when I accelerate, etc. Thanks to anyone who can help me on this one.