Mostly, I was mad that I would have to remove two trim pieces, the entire air intake assembly, as well as deconstruct the battery tray/box in order to slide the battery out of its compartment, but a $600 cost to have someone else do it motivated me, and I actually enjoyed doing it this morning as it was just a lot of steps without being difficult.

Now I just have to decide if it is really important to go by the mechanic's shop to have the new AGM battery registered/programmed to the car like the manual says I'm supposed to do.