In Server Manager, find the stuck service and double click it. Make note of the service's short name (also known as registry name). For example, POP3 might be called POP3Svc or MSExchangePOP3, depending on your version of MS Exchange.
Find out the PID
Launch a command prompt (for Windows2008 or later, run as administrator).
Type the following, where servicename is the service name that you noted above, and hit Enter.
sc queryex servicename
From the results of this query, jot down the PID.
Run Taskkill
Still at the same command prompt, type the following and hit Enter, where [PID] is the PID that you just wrote down.
taskkill /f /pid [PID]
This will forcibly kill the frozen service. You can now return to Server Manager and restart the service.