How to train fire eel to accept other foods

I bought a 6 inch fire eel and it feeds on live river shrimp without problem, as that's what it was being fed on in the LFS.

However, I'd like to get it to feed on frozen foods (eg bloodworm) as it would be cheaper and more convenient than going to the LFS every so often to buy live food.  Whenever I put any frozen bloodworm in front of it, it ignores it.  How do I train the fire eel to accept frozen foods?

Thanks

Hi best idea is to not feed the eel for a day or 2 then try and feed some frozen bloodworm,or cockle prawn etc,for 2 days if not successfull feed some live shrimp again then do the process again? You can feed the live shrimp with flake so that the eel gets some extra goodness O0
You could also try live earthworms?