Disassembly is the process of taking a product and breaking it into materials. There isn't a specific disassembly feature in Katana, but there are ways to trigger the required inventory movements.
Products manufactured in your workshop
If you manufactured a product yourself, you can revert the Production status of an existing MO from Done to Not started or Work in progress. This reverts the stock movements (i.e. materials are added back to stock and the product is eliminated from stock). You can then delete the MO to eliminate it from your Schedule.
Purchased products
If you're taking apart a purchased product, you can create a stock adjustment. You can decrease the product stock and increase the material stock with a single stock adjustment. You will have to define the materials you are creating with a disassembly manually in the stock adjustment, as the stock adjustment cannot be based on the Product Recipe of the product.