If it is a small area, use a wet concrete saw. You will use this like a grinder, using it horizontally, as opposed to vertically, to wear down the hump. This should take down the hump rather quickly. You will need less than an hour to complete. You can generally rent this tool from your local hardware store.
To get rid of a concrete hump in the slab you will need to grind the concrete until it is level. Concrete griders can normally be rented at your local home improvement store. Lay a four foot level on the floor to ensure you have ground enough concrete.
Use a hand chisel or hammer drill and bust out the concrete hump. The concrete can be patched flat by using thinset mortar that you are installing the tile with.