Get a Styrofoam packing box, some fish bags, some old newspaper/packing paper, a rubbermaid tub, and some hurricane tape. Bag the fish (as few in a bag as possible) with about 1/3 water to 2/3 air ratio if possible. Double bagging is also a good idea. Crumple up the newspaper to pad the inside of the Styrofoam box (this also helps insulate the bags against heat loss), and put all the fish bags into the box. This will help keep the water temp stable, and it'll be nice and dark to help reduce stress. Put substrate and filter media in the rubbermaid tub with enough water to keep both wet to preserve the bacteria colony. After the tank is completely drained put hurricane tape in big X marks on all glass sides of the tank to help reinforce the glass (and if the worst happens the glass is less likely to go everywhere).
