It can be done, but it is not cheap to do. It runs about $25 per latch, with three needed per case. I don't remember if that includes the key assembly or not. Each latch is just riveted in place so you can do the install yourself if you have the tools.
Only the 1st generation cases use the small flat keys. Some of us need 1st generation keys so please don't throw them away if you make the swap.
You might get lucky and find someone that has a set of third generation cases for sale. Most riders consider these the best cases that BMW offered for the K bikes.
Second generation cases also use the OEM keys but the locks are turned so that they face the bike. Also, the handles are different on the newer cases.