Bricks, Masonry, Asphalt and Concrete - Cutting a slab

Hello-
I have a concrete slab (12'x12') in the back yard that i would like to remove to put grass in. Its about 2" thick-no rebar or wire mesh and has a drain (1'x1') in the middle of it. there is also 2 small steps down to this area. I would like to keep the concrete underneath the steps for stabitily (grass would probably die anyway) so I need to cut around it-maybe 24-30" total cut on the three sides of the steps.
2 questions...
1. can i make these cuts with a small saw? I have an 18V cordless dewalt 6.5" circular saw.
2. do you see any purpose for the drain to remain intact? I was thinking of filling it with quikcrete and putting the grass over it.

I think i will just use a sledge to demo the slab.

Any thoughts, suggestions, comments.......

Thanks for you time.

Best bet would be to rent a gas-powered masonry saw to do the job. Looks and operates like a chain saw, but has a masonry blade in place of the chain. Will go through the slab like butter. Be sure to use eye & ear protection and a good dust mask. Also close any adjacent windows - lots of dust going to be kicked up.

Decide what to do with the drain after you get the slab busted up, but will probably serve no purpose.