it is a pretty straightforward process. if the tank is old and it hasnt been done for a while it can be a problem as they can stick. i use techniques from working on old cars to free them - PB blaster on 24 hrs before i try, if that doesnt work a bit of heat from a blow torch. it is easier with two people one to hold the tank to make sure it doesnt move, and the other to use a long handled wrench to disconnect. Bradford White water heaters are a total pain as they have cheapened out and made the anode rod the hot water supply pipe also, so you have to disconnect the hot and depending on your setup it may take some plumbing work to get it out.
When i put the new one in i use spark plug anti seize on them (the stuff you use when you loosen and tighten high mileage platinum plugs to make sure they dont fuse to the cylinder head)
Also when you see how gnarly the old one is and how much aluminum has gone into your hot water, I stumped up the extra $10 for the Magnesium ones (yes even for the tenants) it has two benefits - the electric potential (EV) of magnesium is much higher than Al , and is even more protective, and I like the idea of magnesium in my water better than aluminium
the guy in the video does a pretty good job
https://www.youtube.com/watch?v=kIpJDHco7hc