Also, it's done for laptops and phones by a huge number of shops in China, which clearly has no shortage of skilled labour. Many years ago I went there with a friend to get his laptop fixed and the customer experience was incredible. The young lady doing it (in a shop of about a dozen others) actually left the stall and went with us to the other shops in the building to buy the necessary parts, and we got to see them being installed and tested. It was surprisingly cheap too, I only learned afterwards that haggling is the norm but we paid the asking price (which was already quite low from a foreigner's perspective!)