How to uninstall anti-virus on my mac?

I installed an anti-virus called “sophos” on my mac partition so that I could scan my windows partition…after I completed the task of cleaning up that partition, I decided I no longer needed the sophos anti-virus….I thought, but could be wrong that all I had to do was remove it from my applications folder. It hasn’t worked so far…I still have the application running in a process under my activity monitor.

Can anyone help me out?