It used to be a fairly normal modification, to cut the spur off of a DA revolver's hammer to make concealed carry easier.
It's no big deal to do, if you're a very careful craftsman. It's also easy to restore the gun: just buy and install a new hammer.
Except for having deleted the single-action option, you will see no change in function.
The best way to do the job is to remove the hammer, and then modify it while it's off the gun. Doing this will teach you all about the innards of your pistol.
There's gotta be a CD or DVD for sale somewhere, that covers removing and replacing the inner works. Maybe Taurus has a schematic you can ask for. While you're at it, get the replacement hammer and stash it away for just-in-case.