2003 Silverado flash the new steering colum
 

I'm looking for some advice here. I am about to but a 2003 Silverado 4.3 2wd 5 speed. Only issue is the steering colum is out of the truck the guy im,getting it from said someone tried to steal the truck and cut wires for the ignition. I was wondering I I got a new colum key and harness will I have to take it to a dealer to get it flashed. Or is it possible to get the computer steering colum key and all and just do that. I've heard it may be possible to learn the new key to the computer by doing some steps just can't seems to find any clear answers anywhere. Any advice will be very much appreciated and thanks in advance.