usually they are only 2-3 inches thick and NOT reinforced. a sledge hammer will work, but wear safety glasses as concrete shards will go every where. eve if it is 6 inch thick you can do it, just a little more work!

one thing though, is this pad part of the house foundation? i have 2 central units, 1 of which the pad was poured at the same time as and as part of the slab!

We were in the same position as you. We hired a concrete company to use an electric saw and cut the lines for the part that needed to be taken away - about 18 sq. ft split between both sides of the condenser. Our pad was an extension of the slab under our family room so we had to be careful. Once the cuts were made, and they started sledge hammering and jack hammering it out, we found that ours was 6" thick. Under it was the normal crushed gravel that one finds under concrete. The crushed gravel also had to go so that we could add good soil and plant grass. We did this 2 1/2 yrs ago and the cost was $600.

Concrete blade for circular saw: 75$
Electric Jack Hammer rental: 65 $
Cost in Gas to take concrete to the dumps :10$
Cost of medical treatment for herniated disk: $20000

Just kidding. Rent the Jack ,and landfills often take concrete for free.