This is how to program your Chevrolet Impala keyless entry remote fob yourself at home for free.
This will work on Chevy Impala 2006, 2007, 2008, 2009, and 2010.
There is also a video tutorial below so you can see how easy this is done.
2007 and up Silverado Sierra Tahoe Suburban Escalade remote instructions image

Switch ignition ON.
Press vehicle information button Fig. 2 [A] until PRESS TO RELEARN REMOTE KEY is displayed.
Press set/reset button Fig. 2 [B] until REMOTE KEY LEARNING ACTIVE is displayed.
Programming mode activated, proceed as follows:
Press and hold LOCK and UNLOCK buttons on first remote transmitter simultaneously for 15 seconds.
Wait for acoustic signal (indicates correct programming).
Repeat above procedure to program remaining remote transmitters.
Switch ignition OFF to exit programming mode.
Remote transmitters can also be programmed using diagnostic equipment.
NOTE: A maximum of 8 remote transmitters can be programmed.