I am against cutting fan leaves for any reason other than disease such as fungal infections.
If the leaves are drying up so much that you can crunch them with your fingers however, you are probably suffering from some sort of nutrient def or burn.
If more than half the leaf is dead, cut it off including the stem with a sterilized pair of scissors as far back as you can to avoid any infections.
More importantly, if the leaves were dying naturally from old age, they should just turn yellowish and fall off. If this is the case you could easily pull them off once the stems become weak.
If this is not the case, and the leaves are curling and crunchy but can not easily be pulled off you should trim them as far back as possible and then fix your nute problem
