There is this why stuff on the underneath of one of the palm fronds on our Christmas palm. Looks to starting on a few others too. Can I just cut it off or is there more I need to do. 

Second pic is of another frond on the same tree - doesn’t look good either but doesn’t have the white stuff on it. 
 

Any suggestions on what I can do to help it? 

I would say white louse scale, definitely insect damage but I have never seen that type of patterns before. And the second picture looks like potassium deficiency. Or some kind of leaf spot, does the entire plant have the same look as potassium deficiency, one would think by the insect damage an undernourished plant that is susceptible to insect attack. So those two would go hand in hand together. And the leaf spot is more of a fungal issue. Iam leaning towards deficiency. Perhaps a few others on palm talk may suggest otherwise, sometimes it may many other things that all look similar a complete soil analysis and leaf test in a laboratory would pin point it completely. Good luck but whatever it is your plant is suffering.