I’ve done this a million times, I just found it useful to publish it for easy reference

C:\Program Files\IIS Resources\SelfSSL>selfssl /T /N:CN=www.tempuri.org /K:1
024 /V:5000 /S:232294796 /P:443

/T: is to make it trusted

/N: is the common name

/K: is bit length

/V: is days of validity

/S: it the Site ID, you can get this from the log prepend (see below)

/P: is port

To get the site ID, open IIS, and check the log settings.