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After unplugging the hot tub, coil the power cord. If your tub has a storage compartment for the cord, open it and place the cord inside. If the cord detaches from the tub, disconnect it and store it in a safe place until you unload the tub at the new location. For many models, you’ll use a Phillips head screwdriver to open the access panel. After opening the panel, you should find a drainage spout. Thread a garden hose onto the spout, then place the other end of the hose where you want the water to drain.  Drain the water into the street or a gutter instead of your lawn or garden. Your plants won’t like chlorinated water. Drainage procedures vary by model, so double check your owner’s manual. Turn the valve and wait for the water to drain, which can take at least 30 minutes. After draining the water, dry the tub thoroughly with a towel. Once you’ve drained and dried the tub, remove the hose and close the access panel. Replace the access panel’s screws so you don’t lose them during the moving process. If your hot tub has a removable cover, take it off and transport it separately. There’s a good chance it’ll get damaged if you leave it on during the move. Check your owner’s manual for specific instructions about removing your hot tub’s cover. You’ll likely need to unscrew its hinges, so be sure to keep the screws in a safe place until you reinstall it.

Summary:
Disconnect the tub from the electrical outlet. Open the drain access panel and attach a hose to the spout. Open the valve and drain the water. Remove the cover.