Well, division is what it needs, if you want it to bloom like it used to. That's just the way irises are. If you're unable to dig it up yourself, perhaps you can coax a friend, family member or neighbor into doing it for you. My experience has been that I'm usually able to divide the tubers by hand, once someone has dug up the clump for me.
I have better luck using a digging fork, rather than a shovel. If you have 2 digging forks, they can be used to break apart the main clump when it comes out of the ground, so you have more manageable sections to work with.
I have a friend who wants starts of some of my irises. She's 20+ years younger than I, and offered to do the digging. I'll be out there to make sure everything is done correctly, but I'm really not worried. She has a lovely place of her own.
"Isn't it enough to see that a garden is beautiful without having to believe that there are fairies at the bottom of it too?" - Douglas Adams