Thanks for the reply. Unfortunately, mine most certainly has guards.
However, using the image provided by davect01, I could tell where the drain plug and filter needed to be. Based on that it was clear which splash guard needed to be removed. I might as well say, THE splash guard needed to be removed since it pretty much covers the bottom of the front end of the vehicle.
I had to take out 13 clips and 6 bolts. Needed a slotted screwdriver and another small socket for the bolts. Removing the clips was much easier than on any other car I have owned. Perhaps I am getting better at it, but I think that they are designed a bit better. Overall it was much easier to remove the splash guard than I was counting on. Getting it back on and figuring out which of the holes needed a clip took a little bit of work, but again it was straightforward.
I have now changed the oil in our Scion iM. This will very likely be a once-in-10,000 miles activity for this vehicle.