Sometimes, it becomes necessary to move a tank, which can be a real pain in the rear if it's a bigger tank. It also is good to get your tank on a stand before filling it. In the same vein, it sometimes happens that you need to move, and an aquarium is one thing that you don't know about moving. It's a pain, but it's doable.
Drain the tank to about halfway. Save the water in a few buckets.
Turn off the heaters and filters. Depending on how big of a move, it might be necessary to remove them.
Catch all the fish and distribute them into the buckets. If freshwater, plants are best put in the buckets with the fish. If the tank is saltwater, place your live rocks into the buckets as well. Fish can survive a few hours to days in the bucket. Moving a heater over to the buckets with fish is ideal to ensure as much comfort as possible while displaced.
Drain the tank fully, leaving only the substrate
At this point, a large aquarium is possible to move, usually with assistance. Move the tank to the desired position, making sure that it is where you want it. It's almost easier to pull everything electrical out of the tank so that you can rework your cables in the new tank location.
Carefully fill the tank so as not to disturb the substrate too much. Fill it until you can safely operate the heaters, which you will turn on at that point.
Replace the fish and decor in the tank to your liking.
Fill the tank full of water, and resume operation of your filters and other devices.