Prepare for the Installation
Before you start, check these next points to make sure you're ready to go when the new water heater arrives.
Check the Plumbing
Measure the center-to-center dimension between the hot and cold water pipes on the top of the water heater and try to ensure the new heater has the same dimensions. That will make the plumbing job a bit easier. Take a look at the plumbing connecting to the old water heater. Make sure you have a gas union in the gas line if you have a gas water heater, and make sure there is a water shutoff for the cold water inlet pipe and a union connector for the hot water outlet pipe. If you don't have these you're job is a bit harder as you'll have to cut the pipes to remove the old heater, then install the cold water shut off valve, and / or gas union or hot water pipe union. But most plumbers did the right job in the beginning so hopefully everything is in place.
Setting Up
Getting the water heater off the truck and down the stairs (if you have a basement installation) is a two person job. I also recommend renting an appliance dolly if possible. For around $20/day it makes bringing the new heater down and the old heater up a lot easier. They are bulky and heavy. Once you have the new heater brought down to the location of the old heater you're ready to go.
