Using Url rewrite to "delete" a folder

Hello, I have a website that I need to use URL Rewrite to do certain things:

Server: Windows Sever 2012 R2

Website:http://www.contoso.com

Sub-website 1:http://www.contoso.com/site1, default page is default1.aspx

Sub-website 2: http://www.contoso.com/site2, default page is default2.aspx

#1: For both sub-websites, I want to remove the site path. That means, when accessing the two sub-websites, http://www.contoso.com/site1/default1.aspx will become ttp://www.contoso.com/default1.aspx, and http://www.contoso.com/site2/default2.aspx will become http://www.contoso.com/default2.aspx.

#2: When accessing http://www.contoso.com, it will auto load the default page of sub-website 1. That means i want to make default1.aspx as the default page of the main website.

Thanks for the help!