How to remove folder name from IIS with rewrite rule in web.config?

I have a Default Web Site that comes with IIS installation, then I have a few web projects, let's say project1, project2, etc. When I access to one of that projects I need to type an URL like this: localhost/proyect1/index.php or localhost/proyect2/home.php.

How can I edit the web config file to Rewrite the URL to localhost/index.php or localhost/home.php?

I have tried several write rules but none of them seems to work... If there another way to do this I'm open to suggestion. And Thank You BTW.