There are certain ways to desolder components. The most common way is to use a solder sucker. But it is quite difficult to use and usually make the PCB unclean. Another method is to use a solder wick. This is the best known method to me and can remove components without messing the PCB. For SMD components, it could be also useful to use hot air gun with a component pickup tool.
Here are videos for these methods.
[media]http://www.youtube.com/watch?v=Aw4lZGk90i4[/media]
[media]http://www.youtube.com/watch?v=htrcZuK_ZsY[/media]
[media]http://www.youtube.com/watch?v=CuH3dWHipKI[/media]
[media]http://www.youtube.com/watch?v=gP0FVoHZvMI[/media]
How to desolder components properly
Re: How to desolder components properly
See TRONIC.LK for soldering related accessories.