I remember that when my clutch started sticking, I tried to fix it (being young and dumb) by putting a huge spring between the clutch pedal and the dash frame. I had to use all my strength to push it down. It helped quite a bit, but the clutch continued to slip some until I took it to a garage that belonged to a friend of my fathers. They told me about the pilot shaft having too much play, but I dont think they told me how they fixed it, and my father said he'd take care of the bill, so I dont know how much it cost.
All I know, is that because of me driving around for a whole year with the gorilla spring on my clutch pedal, my left leg is still bigger than my right leg, and its been almost 40 years - lol.