1. Download the SelfSSL from microsoft downloads
2. Install it, duh.
3. Assuming you installed it where its supposed to be, go to C:\Program Files\IIS Resources\SelfSSL and run selfssl.exe
4. Agree to it installing the certificate for you and press Y
5. Open your IIS Manager > Sites
6. Right click on the Default Web Site and choose Edit Bindings
7. Add
8. Select type as https and select the certificate you just installed.
9. Done

Viola!

This adds the certificate for only a puny 7 days. If you’re like us, you’ll probably need a cert for a much longer period than that. No problem!
Fire up your command prompt and cd to C:\Program Files\IIS Resources\SelfSS\
type the following:

selfssl.exe /V:3650 /t

That’ll give you a nice cert for 10 years.
But wait, you’re original cert is still there! Wel’ll have to remove it.

1. Start->Run->mmc.exe
2. File -> Add/Remove Snap-in
3. Certificates (on the left column)
4. OK
5. Navigate the tree to: Certificates -> Personal -> Certificates
6. Delete the original SSL cert you created (see the expiration date differences)
7. Follow the above instructions in customizing your IIS to the new cert now. =D

Note: This is used for development purposes and the certificates will be recognized as invalid for that domain. Go ahead and add the security exception in Firefox, IE, Chrome or whatever other browsers you’re using.