Removing a concrete walkway can be a major undertaking, but with the right equipment and a little know-how, it can be done!
In this job, the rental department at your local home store can be your best friend. You can rent some heavy-duty demolition tools relatively inexpensively. Depending on your physical abilities, you may want to get any of several sizes of air hammers. The largest you can handle will be the most effective.
You probably will want to avoid the very largest, but the second-largest can be very effective. If you try the larger models at the rental desk and don't think you can handle them, you can find them the size of a reciprocating saw. They're much easier to handle but they'll take a lot longer to complete the job.
Note: Even with a large unit, the work is slow and hard; plan on renting the air hammer for at least two days. Due to the unaccustomed difficulty of the work (and the fact that the vibration of the air hammer can upset your stomach or initiate a headache) DO NOT rent the tool for two consecutive days. Do one round, relax a few days, then try again. If possible, take turns on the air hammer with a friend or friends.
Step 1 - Set up the Air Hammer
The air hammer will probably come with a few different bits; choose a chisel-nosed one. Read the instructions and familiarize yourself with all controls. Plug the air hammer into a power source using a heavy-duty exterior power cord.
Step 2 - Get Ready
Equip yourself with safety goggles, a dust mask, heavy work gloves, and sturdy work boots. In addition, you may want to make sure your legs and your hair are covered.
Step 3 - Start your Engines
Start by positioning your hammer bit in a natural crevice, like the incised line between two walkway squares. Grasp the air hammer firmly and brace yourself to keep control of it.
Step 4 - Work the Area
As the hammer vibrates, it chips small bits of concrete away. Let it rest in one spot for a minute, then move on. You'll soon get the feel of it and will be able to move methodically across the walkway.
Step 5 - Clean as You Go
The first couple of inches of poured concrete is usually very smooth and fine, and when air-hammered, it takes on the texture of talcum powder. This fine dust gets back into the areas you're working on and obscures your view. It's helpful to have a friend sweeping out the areas you've been working—after you've moved a safe distance away. Further down you'll encounter aggregate, which is easier to work with.
Step 6 - Break it Up
After you have created a fissure in a big piece, you can break it into smaller pieces by enlarging the radiating cracks you've made. When the big pieces have become many smaller pieces, you can break them into easy-to-handle chunks using mallets, sledgehammers, chisels, and other smaller tools.
Step 7 - Haul it Away
You'll probably want to take the debris away to the dump. It's heavy and messy, so you may want to consider renting a vehicle to transport the concrete. Your local home improvement store may have pickups to rent by the hour; a cheaper solution is renting a small moving van for a day, although you must make sure to thoroughly sweep the van out afterward.