Reprogramming keys question

[savi18]

Hi All

Rebuilding a poorly maintained 2001 Ka, All door locks are faulty which turns out to be just worn out, i have now bought a damaged 2001 Ka with same exact color, i am going to swop both doors and tailgate as the paint work as faded but not on the new doors, will also be swopping the ign barrel, can i get the old keys off the damaged Ka reprogrammed to the ECU on my car, i believe getting to the ECU is a pig of a job to get at and remove, reprogramming sounds a lot easier if it can be done. Cheers