Remove the fill valve.
Toilet lock nut clockwise.
Then finish loosening the nut with your fingers.
Step 3 replace the valve.
Lock nuts are used to hold fixtures securely in place from below.
Raise the pipeline from the overflow tube.
Gently pull the nut down.
I then would proceed counter clockwise with a second offset 6 pipe wrench and try to loosen the nut.
Empty the bucket and place it underneath the water supply line.
Tightly secure the lock nut washer and nut.
Prepare the toilet turn the water supply shutoff valve clockwise to turn.
If the nuts don t have wings lock a pair of locking pliers around each one in turn.
While turning these stabilize the bolt from above with a screwdriver.
Remove the nut washer and lock nut.
Some nuts have wings that you can grasp with your fingers.
The lock nut threads onto the fill valve inlet just above where the water supply hose or tube coupling attaches.
Use your pliers to loosen the nut under the tank.
Use a pair of pliers to just loosen the coupling nut.
Position the new valve in place of the faulty one.
Locate the coupling nut on the underside of the toilet tank.
Using various methods to remove the nuts and the bolts when the toilet bolt won t tighten gets your project back on track.
These are used in a toilet chiefly to secure the fill valve in the toilet tank.
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.