Washer cut in half, two rivets to stick out/down into notches, weld a handle on the washer or slots to tap it around or vice grips or two rivets sticking up close together for a bladed screw driver or.... This is called a spanner wrench. Maybe you can use the whole washer, you didn't say what kind of access you have. Needle nose pliers? retaining ring pliers? New faucet?


Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn