It is a bit like a puzzle- you need to look at what is where and determine which way will be easiest to move the blower enough to access the rod. The fitting on the hot side would be the easiest to remove without risking disturbing any of the other joints. If the heat trap breaks off when you try to unscrew it from the top of the heater, then you have another problem. I'm shocked to see you are still going ahead with this give all the feedback from the pros. I would speculate that 97% of all water heaters do not get an anode rod replaced during their time in service.

One thing that would be good for you to do is to buy a couple of fittings and a section of pipe to do some practice solder sweating copper. There are a million good "how to" articles and videos on the web for reference. The most important rule is not to burn the house down. It's harder to put out the fire when you have the water shut off too.