I would suggest manual removal as best to your ability and then try dosing hydrogen peroxide which works wonders. If you have a substantial algae issue, try figuring out the underlying cause and address it for long term success. Happy new year and happy reefing!
Yes, you can dose directly to your display tank. 1ml of 3% hydrogen peroxide for every 10 gallons, dose every 12 hours. Be patient with your expectations but it can work wonders and is safe for your tank. If you have zoas, they will probably close up immediately but will open back up shortly thereafter. You'll probably notice improvements with water clarity as well. Good luck.
I had extremely good luck with Vibrant (along with good aquarium maintenance). While I didn't have a severe case, it is totally gone within two weeks of dosing.