I do 1st/2nd to 3rd gen steering racks swap every day for a living (done this to myself too). The procedure is quite simple, as long as you know where to go and what pin codes to enter
Most probably you have yellow steering wheel light on the dash and few trouble codes stored in both Steering Assist & ABS/ESP ecus.
If you couldn't manage it locally I think I could help your mechanic finish this job by-air.