
If you are lucky enough to win one, Howrse will let you know by sending you an email (on your Howrse account). Then you need to go to the Black Market, choose 'Horn of Plenty' and open one. Make sure to select from the one you have in your stock and not to use a pass to buy one!
So how do you find 5 Xanthos? There are several ways, but our favourite is to use one of the Xanthos lists. Not only are all (or most) of the Xanthos' listed in one place, some lists have an automatic stroke feature. This means you just click on the link to a Xanthos and is stroked automatically. The easiest list we know of is in the EC forum owned by the Moderator 'funnyone'. You can find her in the list of 'Mods' at the top of the Event forum page or the Game Play forum.
We tend to win a HoP (and 1000 equus) a couple of times a week. And getting free Black Market items in a HoP is really pretty fabulous. So make sure you get your '5 a day' and good luck!
UPDATE: We've kindly been sent a link by CraXoR, who used to play on Howrse. This link allows you to stroke 5 Xanthos' at once! So here's the link for you: Instant Xanthos Strokes
Patsy