Let's Kill a Tarrasque!

So, I really, like, REALLY want to gm a one shot where my players fight a Tarrasque, I know it's a monster beyond "common sense" game wise and I know my party needs to be very well prepared, that said:

How can my party prepare for this fight? What itens should I give them, permanent and consumable? How many gold? What classes? What strategies? I want to know everything.