To kill a process in Batch you can use the snippets below.
If you dont know how to retrieve the PID you can use our other snippet List all Processes in Batch.
taskkill /PID 1292
if you want to force the taskkill you can use /F.
taskkill /F /PID 1292
if you want to taskkill the process by name you can use the follwoing snippet.
taskkill /im notepad++.exe
for more informations see the msdn TASKKILL