I need to know the name of the tool that can be used to remove the plug on the main sewer drain. The drain is recessed so I cannot use a regular wrench to reach it. The plug has a square nut type of protrusion which I am sure was put there to open the plug with the right tool. I just don't even know where to go to find this tool or what to even ask for.. so the name and most likely place to find one would be helpful.