How to increase will power?

What are some Buddhists techniques by which I can increase my will power? I lack will power which is basic to practice 8fold path. I don't have will power which makes me stray to be consistent on spiritual practices. Please shed light on the ways to increase will power. Edit: If someone says "You should do AnApan to increase will power" then I need will power to do that **consistently** AnApan, so such answers doesn't completely help me. Please tell any alternative. Maybe some practice which gradually increases will power.