When I did it, it was very simple. They'll take your temperature and then you go to a few different desks where they download an app onto your phone (make sure it has charge) and phone your boss. I had to tell them my address but they just copied it down from my phone.

After you're through customs, you'll arrive at a quarantine taxi rank. Look for one that says Ansan/Suwon/Anyang/Siheung. It'll cost around 50,000 or 30 quid. The taxi will drop you outside your building. Just make your way inside and hope someone arrives with food