How do I start/stop IIS Express Server?

I have installed MS Visual Web Developer 2010 which includes IIS Express.

Before this, I had installed XAMPP server for my php applications.

I would like to know how can I stop IIS in order to be able to start XAMPP? It appears that they use the same port. I guess those could be changed, but I do not want to interfere with other programs, and more than that I think this should be simpler.