Generally, you can't. Once a toddler is in to a tantrum, he can not hear you. He is overwhelmed with the powerful feelings he is feeling and has blocked out the outer world while he deals with it. Trying to talk him out of it or jolly him out of it will backfire and make it worse.
When he throws a fit, ignore him. If he's a head pounder, carry him somewhere safe enough to bang his head. Then ignore him. Stay in the room so he has your presence near by but don't interact with him. The more attention you give him, the more you reinforce the behavior for the future. Your goal is for him to find an appropriate way to deal with frustration, disappointment, anger, and other powerful emotions in the coming years.
at 12:47 AM on Jul. 16, 2009