To get you started on how to manage processes, here several examples:
1.get-process
2.get-process winword
3.get-process -id 3032
4.stop-process 3868 <-- to stop process with pid
5.stop-process -name notepad
6.working with WMI
Get-wmiobject -class win32_process -computer HOST1
-credential $cred|select Name,Handle,VirtualSize,WorkingSetSize
| format-table