Not all the fighting will be done with guns and bombs.
The USA and UK have been dropping leaflets on Iraqi bases for a long time.
This is to try and persuade Iraqi soldiers to give up by offering them freedom, and showing just how powerful British and American weapons are.
If Iraqi soldiers don't think there is any point in fighting, this could be a very effective way of ending the war quickly.
The USA may also try and take over Iraqi radio to talk directly to the people without Saddam Hussein interfering.