Okay, replaced my countertops. In the process, removed sink, yada yada yada. When putting sink back in I couldn't get that metal ring to screw ( I think it's threaded) off of that threaded collar that goes underneath into the disposal. I have to find a way to get it off because it leaks underneath at the collar in large part because the gaskets are old. Is there a special tool for this or what. Help!

I tried fixing a leaky bathroom sink faucet, just to find a completely different type of two piece plastic stem with the washer not screwed in, but having a little spring and cap type washer instead. I did not find which part was diffective (cold was tripping), so I just reversed all the parts and temporary shut off hot altogether. Are these types of faucets fixable? If so which part usually wears out, the spring or the rubber part? Turns out my whole bathroom has these types of stems. The cold water in the tub leaks from the knob every time the water is on (at least not continuously) This one also opens the opposite way (not lefty loosy righty tighty) and has hot and cold reversed. All I care about at this point though is to figure out how to repair plastic stems with springs.