Good to know! Replacing mine (20+ years old, but I drain it regularly) was on the Things To Do list this year. Last year was new attic insulation.
It’s always SOMETHING with, ‘This Old Dump!’ :)
Get the anode replaced, that will do more to make the tank last long than anything else. You don’t even need to drain the heater.
You can buy one from nearly any supply house, they are inexpensive. Cheap, actually, compared to a new heater.
To replace it:
1: turn off both the input and out water on the pipes near the tank.
2. use a wrench, a socket wrench works the best, to remove old anode. The anode will have a hex head, like a bolt. It is screwed in from the top of the heater.
3. insert new anode, using pipe dope on the threads, tighten.
4. turn on water.
If the old anode is used up, make sure to install the next new one sooner.