First of all, my compliments to all you homeowner, and maybe some pros, for calling the animal it's correct name, eg. WATER HEATER as opposed to the oft erroneously stated, "HOT" WATER HEATER. Also to those who would be so emboldened as to install a water heater by themselves. when soldering the COLD water supply , REMEMBER not to apply heat too close ( probably within 12 ") to the top of the unit at the point of the inlet. There is a plastic fill tube inside the water heater at that point and any flame/heat applied too close to it will cause the lip of that tube to melt and fall into the tank . If THAT happens, you'll never have HOT water. Warm maybe but never HOT.
Other than THAT and possibly breaking ones back hauling out the old sediment filled tank, IT's A SNAP.
Betty, the BRIGHT side of this is when/if you sell your house, the listing will high lite "ALL NEW........................."
Mark
PS: And I almost forgot, when taking the old unit to the curb for disposal, place it at least three neighbors over lest it catches the eye of a municipal inspector who would cite you for doing this installation without proper permit. Your neighbor could play dumb much easier that you could.