NBC is already distancing themselves from Jay Leno ... by erasing his name off the side of the building where he shot "The Tonight Show."
The Peacock network sent a team of painters armed with rollers and a forklift to white-out Jay's billboard -- just ONE FRICKIN' DAY after he signed off for good.
Here's what's interesting ... Jimmy Fallon's moving the show to NYC, so the net's not really under a deadline to change the signage before Jimmy takes over the reigns. Guess they just wanted to let Jay know that this "goodbye" is permanent.
Somewhere, Conan O'Brien is smiling.