Getting rid of us would be hard. I think you have the cases reversed.
Based on our current trajectory all it seems to require to me is a basic plan and a bit of patience...
It’s remarkably hard to actually eradicate all humans.
You don't have to eradicate them all.
Wait for the robot workforce to be deployed, then visit a few deadly pathogen storage facilities. Society collapses and then you send in the murder bots, or you just ignore the ants.
Humanity has wiped out lots of species without deliberate organised effort.