Question
I've already cut all damaged fronds back to the trunk but I don't know how to identify what part of the "bamboo-like" trunk had damage if any and what to do with them?

Answer
Now it is time to be patient, you have done everything you need to do from a pruning standpoint, when new growth commences, you will have a better idea on what is viable and what isn't; keep it properly watered and wait and see. When new growth starts from the center of the existing canes, let me know, and then some final pruning will be needed. Nick