If you got warm/hot air after doing the above procedure, then you probably did it correctly. You say the radiator is full but how about the reservoir? In the past, when I've done this, I've over filled the reservoir to insure that any air in the system is replaced with coolant from the reservoir.
My suggestion would be to do the procedure again, raise the front of the car as much as you can (2 or more feet is good), do it exactly as above (or look on youtube for a video, check this link out -
Altima No Heat ). Also, I remember too that if you can hear what sounds like a sloshing noise in your dash when you turn a corner, this is a good indication that there is air in the system.
In the video, this guys uses an external reservoir instead of using the Altima's reservoir. Most of us don't have these, and why make a jug as he suggests when you can use your own reservoir sitting right there at the fender.
This video is excellent on how to correct this problem
Good luck!