I'm with Scuba. Your project is definitely doable as a DIY, but breaking and carting all that material yourself is going to be back breaking and require a whole lot of time.
Also, if you end up removing lots of cement and fill you'll need to get some topsoil carted back in.
That being said, you can rent a jackhammer (electric or pneumatic) and a truck from Home Depot and go to town..
Or look up "urban landscaping" and do lots of potted plants and astroturf.. :laughing: