There is a button next to all machinery, that will disassemble the machine when clicked. You will get back half of the resources it initially required to manufacture the machine. These resources will be available at the completion of the disassembly project.
You are required to have the same tools as used in the manufacture of the machine in your inventory. An exception to this rule is that every machine that require a iron, bronze or wooden trowel in manufacturing instead requires a sledgehammer to disassemble.
For machines that require objects to assemble, these objects are always returned in full.
Disassembly of small wooden carts, longboats and dinghies was introduced in February 2014, and they all require an axe to sucessfully disassemble. They also need to be completely empty of people, docked vessels, resources and objects.
Cancelling a disassembly project will start a project to repair the machinery that was being disassembled. No resources are needed for this repair, but any progress made in the disassembly has to be re-invested in the repair, before the machine is as new again.