Strangely Truculent Unicorn Portaled Inside Demesne!

"An angry blue unicorn popped up in my den. How do I get rid of her?"

"An angry blue unicorn popped up in my den. How do I get rid of her?" How does a human address this uniquely distressing dilemma? (Probably better than Trixie does.)

Era: Season 8 assuming this disaster is never mentioned again. Later if you think it should be mentioned by somepony.