change the ignition swich cilinder new key

hi yes i do have the old pats and the green light is flashing what do i do ??

On the old assembly take the immobilizer receiver ring off and swap it onto the knew lock assembly , should be 2 small screws and it's already unplugged , you might want to have the steering column trim off , so you can compare to new one , it is on green colored connector. there are 2 separate plastic pieces , only the first piece with the 'ring' needs to be swapped.Only problem , I now realize , is that you didn't know about this first so now I feel like an idiot......we always have the switches re-keyed to the original key first.IF you didn't break the bolts for the bracket yet , it would still be cheaper to take it back off and bring all pieces to a locksmith and have that done.IF you did have it re-keyed first , then you're safe on that , sorry about the goof, but if you do this , then you won't have to deal with 2 separate keys either.