Once you have removed the dust cap and drive flange, you expose the axle stub shaft were the wheel hub nuts can be accessed.
To access the spindle threads start by unbending the locking tab of the lock washer.
Using a 54mm hub socket, remove the outer hub nut.
With the nut removed you can access the spindle threads. This is where the tool will screw on.
Before screwing the tool to the spindle, press the axle stub shaft from the outside to expose and view the spindle bushing.
This photo shows the bushing with no grease on it.
Now thread the tool onto the spindle. Ensure the axle stub shaft is properly aligned with the inner bore of the tool. You may need to manipulate the CV boot end of the stub shaft to start the treads.
Attach the grease gun to the grease zirc and push grease into the cavity until grease is seen at the brass bushing. You will notice the axle being pushed inwards. Continue until all dirty grease is pushed out.
This shows the grease that has oozed past the brash bushing. The bushing/needle bearing is now properly packed.
This shows the brass spindle bushing and needle bearing. The needle bearing is inboard of the brass bushing. The face of the brass bushing is visible from the backside of the knuckle when the axle is pressed inwards.Here is a video showing the how the grease pushes the axle back and then eventually oozes past the spindle bushing. This gives an idea on how much grease is needed to fill the cavity between the axle and the spindle and pack the needle bearing. The pumping sound is a pneumatic grease gun.