The serpentine belt is relatively easy to replace. You may find it beneficial to put it up on ramps, and have someone under the car help route the belt/hold it in place. There will be the ABS lines, and AC lines in the way, but otherwise 1ZZ is pretty easy as the belt tensioner itself doesn't round out as easily as the 2ZZ.
I would just make sure you have a long enough wrench/ratchet to be able to get a good amount of pull on it. And when pulling the tensioner to loosen it, when it stops you STOP!!!. Otherwise you will round it out and then have to replace the whole belt tensioner assembly.
I'd say tops of 30min job in the driveway, barring anything going wrong.