Water heater maintainence

[jp1]

In a random conversation with contractor today he mentioned this. Apparently there's an anode pole that goes from the top of the tank into it to attract certain minerals in the water that like to eat metal. The pole gets eaten up so that the metal of the tank doesn't, giving the tank a longer life. The one video I've watched on this (link below) makes it look relatively easy to DIY. The video mentions that some tanks it's open access on the top of the tank and others it's under the cap that is attached to the top with screws all around the tank. That's how ours is, which makes it a bit of a headache to do. Were any of you even aware of this? I'm doubting anyone has attempted this repair on their own. It seems reasonably straightforward but I'm nervous about having to disconnect the flu thing, get the top of the tank off, etc. The video also said removing the old one may require cutting it as you pull it out since it's a several foot long piece of metal and our hot water heater is in a little closet with limited space above it so that would have to be done in our case. (The replacements come in attached segments so it can bend every foot or so. Our water heater is relatively new so it might even have one of that design in it already which would be awesome.)

https://www.youtube.com/watch?v=2IUNIUZz4Os