The first step to get an accurate view is to get the most current data.
Here's how to use PowerShell to change a service account password that may be shared by multiple users.
Here's how to easily turn on and off services in PowerShell.
Here's a few different ways to finding services info through PowerShell.
Here's a couple different ways to get the job done.
Of course you could accomplish this outside of PowerShell, but why would you want to?
PowerShell remoting will allow you to locate the expiring certs before they cause your Web site to go down.