Wait until spring to cut back the plant to help protect the new growth in case another freeze occurs. Remove only the yellow and brown fronds in the spring as they will not come back. Do not remove green fronds. These articles will help you as well:
https://www.gardeningknowhow.com/plant-problems/environmental/how-to-tell-if-a-plant-is-dead-and-how-to-recover-an-almost-dead-plant.htm
https://www.gardeningknowhow.com/plant-problems/environmental/tips-for-saving-cold-damaged-plants.htm