I'm arriving at Capital airport Terminal T2 with Korean Air and departing at terminal T3 with SAS.

Oh, I see. So you will take the international to international transfer and the MCT is 120min. Well, the general procedures are like this:
Flight Arrival - Transfer Procedures - Border Inspection - Security Check - Custom Inspection - Waiting and Boarding

The procesures are easy to finish. Generally, it is no need to go through immigration. They will just scan your passport at the transfer desk.

For luggage matter, if the former airline has luggage check-through service, your luggage will be directly transferred to the final destination. Otherwise, you will have to go through the immigration to the arrival hall, handle the luggage and check in again.