Install Microsoft URL Rewrite extension using Web Platform Installer. (Web
Platform Installer is a drive-by-download system for installing extensions in
IIS; it's not a local Windows or IIS component.)

at time of writing, download page was here:
http://www.iis.net/downloads/microsoft/url-rewrite

Click "install this extension" to download the stub installer, then run that
.exe file on the web server.

Then, close and reopen the IIS MMC -- a "URL Rewrite" icon should now be
visible on all the sites.