One of the first comments is something I've been saying for a while, about how to admit that you were wrong about something, instead of clinging to a broken opinion out of stubborn pride:

Try to make it a personal policy to prove yourself WRONG on occasion. And get excited about it. Realizing you've been wrong about something is a sure sign of growth, and growth is exciting.

The key is to actually enjoy becoming less wrong, and to take pride in admitting mistakes. That way it doesn't take willpower, which makes everything so much easier.