Unable to bind to port 80 - Bitnami OSQA Apache

I would like to change from port 8080 to 80. When I try and edit the conf file, and restart, I get the unable to bind error.

1) How do I find out which service is using that port? 2) How do I remove that service if its going to conflict? 3) Will editing the conf file again to port 80 solve this?

Thanks,