Login to your server via putty or tunnelier, and in command console type this command :
Now you can view what process are running in the server and PID ( Process ID ) of every process running.
In case you want to kill specified process, use kill command
# kill -9 PID
-9 attribute mean forcing to kill a process. For example you want to kill crond process from picture above, use this command :
# kill -9 1634
To quit from TOP, just type q