Sometimes there is so little space between the bowl of a kitchen sink and the wall that getting a wrench up there is very difficult. And even if you can fit the basin wrench or pliers up there, you sometimes need that second hand to grip the portion of the faucet above the counter. Even my arms aren't that long. 
Here is what I'm talking about. Removing the nut after it's been there a while can be tough. In a pinch, I pull my drill from the van, and drill the nut to break it into sections where I can then pry it off with a flat blade screwdriver.
Once I separate the nut I can then pry it off from the threads.
Another look at a different sized nut that's been drilled.
Many of the newer faucets come with two screws that allow you to tighten and snug it up with a Phillips screwdriver. When it's time to remove, you can loosen the screws and move the nut off with your fingers. At least I think I can. I've got pretty strong fingers you know.
And the new faucet installed. This one is from KWC
Here is what I'm talking about. Removing the nut after it's been there a while can be tough. In a pinch, I pull my drill from the van, and drill the nut to break it into sections where I can then pry it off with a flat blade screwdriver.
Once I separate the nut I can then pry it off from the threads.
Another look at a different sized nut that's been drilled.
Many of the newer faucets come with two screws that allow you to tighten and snug it up with a Phillips screwdriver. When it's time to remove, you can loosen the screws and move the nut off with your fingers. At least I think I can. I've got pretty strong fingers you know.
And the new faucet installed. This one is from KWC
