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