This method is from stevepavlina.com: One night before going to bed have a wake-up training session.

• Set the alarm to sound after a minute or so.
• Go to bed, turn off the lights, take a good sleeping position.
• When the alarm goes off immediately jump out of the bed, stretch, and walk out of the bedroom.
• Repeat the previous steps 10-20 times. The idea is to bypass your brain by preconditioning.

Your brain may be suggesting you various things about getting up, but with preconditioning you don’t give it a change… you are already out of the bed when the brain wakes up to protest :-)

(if you ever fall back to not getting up immediately simply retrain yourself)

I have done that before and it works. Now I have to do it again…