For an aquarium that big you may consider hiring a service.

drain about half or enough water out of the tank so that it can be easily carried, and leave them right in the tank. The other option you have is putting them in bags and I don’t recommend doing that because you will have to net hem and risk removing their slime coat or stress coat on their bodies. Leaving them in the tank with half the water is the least stressful for the fish. They should be tended to fairly quick upon arrival.

1. Your can put them in plastic bag and pump in oxigen and tight it up. 3 hours should be OK. That is how the fishes being tranported for exporting. The fishes even can from Asia to Europe/US, the transport time is more then 3 hours.

2. Put them in a container and supplying them air using a portable air pump which operating by battery. Must use the original aquarium water, don’t use water from paip !!

There are many ways you can do this. However if you have any decor in your tank, I’d remove it ands put it in plastic bags.

Option 1: Go to Petsmart or similar. They will pack your fish for you for free in plastic bags with oxygen.

Option 2. Get a small battery operated aerator/pump. Drain out half the water, put the aerator/pump in and then load up the tank. Cover it very securely, and then drive (14 fish cannot survive in 15 gallons of water- hence the aerator to boost oxygen)

Option 3- I do not know what sort of fish you have. If they are Zebra danios or other hardy fish, then you are unlikely to lose fish if you are sensible about it. However, if you have delicate/expensive fish, you might seriously wish to consider Option 1.

you first drain the tank, to about 1/2 or transfer the fish into a smaller container. Make sure their are enough bubbles and your fish should be fine!