Because it requires noting, given all the bad ■■■■ people say about Magna’s water, that heater lasted 13 years before needing replacement.
Everything is ready to go as soon as the 40 gallons of water are emptied out. 
I will say reengineering the hookups when I replaced it the last time are showing to have been the right move.
That 40 gallons takes longer than you would think when you’re emptying the water heater to fix it, but somehow barely lasts long enough for a couple of showers. Funny how that works…
Only had to make one extra trip to the store. Had to buy a gas nipple to attach the gas line to the heater.
No leaks…no gas line issues,lines all cleared…hot water is on its way.
They’re surprisingly easy - assuming you have the proper connection types.
Congrats! Always feel good when any repair involving water supply, gas, are completed, turned on, and no leaks! Good job.