I am working on my basement floor, and it is very flat and finished, with the exception of a couple spots where it looks like the builder just dumped some spots of excess cement. As I am prepping my basement for a remodel, I greatly appreciate any advice on the best / easiest method to remove these 2-3 "splotches" of cement to level my floor.
For no bigger than they are I would suggest just good ole manual labor. Probably the easiest method would be to get a diamond blade for a skill saw and score it into little narrow sections, then once you've done that go back with a maul and a cold chisel and chip it out. Best case scenario is you remove it so it's just a little below the current finished surface of your slab and use a quick self leveler to bring it back, or if your installing foam backed carpet just float over it if the depression is not very deep.
Dont think those little spots would justifyu renting a concrete grinder.