Water is dripping about 1 drop every second and has been for quite some time. I removed the plastic knob of the cold water handle. This is my friends tub. I did a replacement of the stem on my tub and had a tool which I thought needed to be used for this one but then when I took off the knob I saw it is not the same type. Please see pictures. The first seems to me since there is a flat spot (arrow points to it) and there is another one on the opposite side that instead of using the tool in the photo that I used for my tub stem I should use a good quality adjustable wrench to turn the stem and unscrew it from the assembly. But before I attempted this I just wanted to get confirmation that this is the proper procedure for this type of assembly. Can someone please post a picture of a similar type assembly (parts explosion) so I can see how it is actually taken apart and reassembled. The picture of the back of the wall showing the full assembly I was hoping was enough for someone to recognize why type of assembly it is. My tool slips over the handle (where the plastic piece is) but just slides over the surface and does not grip the stem so I assume this is a different type of assembly. When I did my tub stem it was a washer at the end of the stem that was decayed and needed to be replaced. Is the same thing here? Or do I have to purchase a new stem. Any assistance would be appreciated. Thanks

The blue valve is only for cold water to tank. I don't have a way to shut off the main hot water line. I'm trying shut it off to adjust a hot water valve for a sink in one the washroom. Can u look at the picture to see if there's anything wrong. Should I get someone to install a valve for the hot water line? Why would someone install a hot water line there without a valve?