The first obvious step is to kill (almost) all humans, and from then on nature will wipe out most traces of our societies, as other answers have shown. For large, ancient structures that will last for thousands more years, such as the Egyptian pyramids, I'd imagine you could blow it up with either simple explosives or magic and then it would be unnoticeable withing a few hundred years just like most other structures.
However, this would only make civilization invisible from the surface alone, yet other traces of us would remain for millions of years. For instance, all the road systems will be buried, but they would mostly still be there, and would be detectable with just underground scanning technology (even with just a shovel in some places). This would be very, very obvious, and would be a clear sign of a highly organized society. You would definitely need to grind up all the roads somehow.
Another big issue would be plastics. Contrary to popular belief, plastic does decompose, but it doesn't biodecompose. After a few million years, most plastic in the world will be in the form of microplastics, plastic particles that are less than five millimeters in diameter. The majority of these microplastics would literally never go away, because they can't be reduced into their elementary parts without some chemical reaction. Fortunately, these would only ever be noticed via the technology that we have today, and by the time the new civilization discovers them, they would probably mistake it for their own.
The thing you would have the hardest time getting rid of would be space debris. Currently there are millions of small (and a few very large) man-made objects orbiting the Earth, and more are added every day. You would almost certainly have to resort to magic in order to get all that junk down to the surface.
On a side note, I'd like to add something here: most people are under the assumption that only a few thousand or million years after humans disappear, there will be no trace of human civilization left. In reality, assuming you don't involve alien technology or magic, there will always be traces of our civilization, all the way until it's consumed by the sun billions of years from now.