Always a good tidbit of information to keep around:

To perform a remote shutdown:
1. Open Computer Management (Local)
2. In the console tree, right-click Computer Management (Local), and then click Connect to another computer.
3. In the Select Computer dialog box, click Another computer, type the name of the computer that you want to restart or shut down, and then click OK. You can also click Browse to search for the name of the computer.
4. In the console tree, right-click Computer Management (Remote computer name), and then click Properties.
5. On the Advanced tab, click Startup and Recovery.
6. Click Shut Down to open the Shut Down dialog box.
7. Under Action, select the actions you want to perform on the computer to which you are connected.
8. Under Force Apps Closed, select the circumstances under which you want to force applications to close when you shut down or restart the computer, and then click OK.