If the nuts don t have wings lock a pair of locking pliers around each one in turn.
Toilet lock nut clockwise.
These are used in a toilet chiefly to secure the fill valve in the toilet tank.
Then finish loosening the nut with your fingers.
Raise the pipeline from the overflow tube.
The valve is connected to a rubber ball float.
To be honest before i grabbed the hack saw i would always set up a straight 6 pipe wrench inside the toilet tank and position it at the base of the fill valve with the handle up against the toilet tank.
Use a pair of pliers to just loosen the coupling nut.
Remove the fill valve.
When you unscrew the screw the pliers will hit against the toilet bowl and prevent the nut from turning and it will loosen.
Position the new valve in place of the faulty one.
While turning these stabilize the bolt from above with a screwdriver.
The lock nut threads onto the fill valve inlet just above where the water supply hose or tube coupling attaches.
Using various methods to remove the nuts and the bolts when the toilet bolt won t tighten gets your project back on track.
I then would proceed counter clockwise with a second offset 6 pipe wrench and try to loosen the nut.
Tightly secure the lock nut washer and nut.
Remove the nut washer and lock nut.
Some nuts have wings that you can grasp with your fingers.
Empty the bucket and place it underneath the water supply line.
The end of the water supply line will come away from the connection.
Use your pliers to loosen the nut under the tank.
Step 3 replace the valve.
Locate the coupling nut on the underside of the toilet tank.