Try pieces of fish fillet (tilapia and other white fish) and/or market shrimp first before moving on to pellets; that will help it get used to dead food while still providing it with good nutrition. Once it's on either of those, either start packing the pieces of fish/shrimp with pellets (so it gets used to the taste of them) or give it the freeze-dried krill. After it's feeding on either one of those foods, try giving it just pellets or a pellet/krill mix and slowly wean it on to just pellets. You can always give it pellets during feeding time otherwise during these steps just to see if it will make the switch early.
This worked for me for training my gars to take pellets, and gars and pickerel have a somewhat similar hunting strategy and prey preference in the wild, so it might work in your case, too.
This worked for me for training my gars to take pellets, and gars and pickerel have a somewhat similar hunting strategy and prey preference in the wild, so it might work in your case, too.